1
Contents
Record of Experimental Work Unit 1 ...................................................................................................... 4
Record of Experimental Work Unit 2 ...................................................................................................... 5
Record of Experimental Work Unit 3 ...................................................................................................... 6
Skills and Hints ........................................................................................................................................ 7
Conduct a qualitative test for starch ...................................................................................................... 8
Conduct a qualitative test for a reducing sugar .................................................................................... 12
Conduct a qualitative test for protein .................................................................................................. 16
Conduct a qualitative test for fat .......................................................................................................... 20
Identify any five fauna and any five flora using simple keys. ............................................................... 25
Identify and use various apparatus required for collection methods in an ecological study............... 31
Conduct a quantitative study of plants and animals of a sample area of the selected ecosystem...... 36
Investigate any three abiotic factors present in the selected ecosystem, as listed in syallabus …......45
Be familiar with and use the light microscope ..................................................................................... 51
Prepare and examine one animal cell, unstained and stained, using the light microscope ................ 56
Prepare and examine one plant cell, unstained and stained, using the light microscope .................. 60
Investigate the effect of pH on the rate of enzyme activity ................................................................. 68
Investigate the effect of temperature on the rate of enzyme activity ………………………………………….… 74
Investigate the effect of heat denaturation on the activity of an enzyme ........................................... 80
Prepare an enzyme immobilisation and examine its application ......................................................... 85
Conduct any activity to demonstrate osmosis ..................................................................................... 89
Investigate the influence of light intensity on the rate of photosynthesis........................................... 94
Prepare and show the production of alcohol by yeast ....................................................................... 101
Isolate DNA from a plant tissue .......................................................................................................... 107
Investigate the growth of leaf yeast using agar plates and controls .................................................. 113
Prepare and examine microscopically the transverse section of a dicotyledonous stem ................. 119
Dissect, Display and Identify a sheep’s heart ..................................................................................... 123
Investigate the effect of exercise on the human pulse rate ............................................................... 128
Investigate the effect of exercise on the breathing rate .................................................................... 133
Investigate the effect of IAA growth regulator on plant tissue .......................................................... 138
Investigate the effects of water, oxygen and temperature on germination ...................................... 147
Use starch agar or skimmed milk plates to show digestive activity during germination................... 152
Visuals for Experiments....................................................................................................................... 156
2
3
Record of Experimental Work Unit 1
Experiment Title Unit 1
Date Experiment
Completed
Testing Food for Starch
Testing Food for Reducing Sugar
Testing Food for Protein
Testing Food for Fat
Identifying Flora and Fauna using
keys.
Identify a variety of Habitats
Identify and use various apparatus
required for collection methods in an
Ecological study.
Quantitative Survey: Plants
Method: _____________________
Quantitative Study: Animals
Method: _____________________
Investigating Abiotic Factors
Factors: 1.
2.
3.
4
Date Write up
Completed
Questions
Completed
Y/N
Record of Experimental Work Unit 2
Questions
Experiment Title Unit 2
Date Experiment
Date Write up
Completed
Completed
Completed
Y/N
Using the Microscope
Looking at Animal (cheek) Cells
Looking at Plant Cells
pH and Enzyme Activity
Temp and Enzyme Activity
Enzyme Denaturation
Enzyme Immobilsation
Osmosis
Photosynthesis
Fermentation of Alcohol
Isolating DNA
5
Record of Experimental Work Unit 3
Questions
Experiment Title Unit 3
Date Experiment
Date Write up
Completed
Completed
Completed
Y/N
Leaf Yeast Growth
Heart Dissection
Exercise and the Pulse Rate
Exercise and the Breathing Rate
TS of a Dicot Stem
IAA as a Growth Regulator
Germination
Digestive Activity during
Germination
6
Skills and Hints
The skills developed primarily through the practical activities include:
• Manipulation of apparatus
• Following instructions
• Observation
• Recording
• Interpretation of observations and results
• Practical enquiry and application of results
Manipulation of apparatus involves manual dexterity and efficiency for example:
•
using appropriate methods in collecting required specimens in an ecological study
•
being familiar with and using the light microscope
•
dissecting a sheep's heart
•
conducting a series of laboratory activities and investigations safely and humanely
Following instructions involves adherence to the instructed or recorded sequence of actions
required to carry out an activity e.g. the ability to follow instructions from a practical manual.
Observation is the most important aspect of the scientific method. All knowledge of biology is based
on situations in which a biologist observes a particular event and records it. Instruments are used to
extend our perceptual limits. Appropriateness, accuracy and completeness of observation need to
be practiced, monitored and guided from relevant theoretical criteria.
Recording is another essential aspect of the scientific method. Records are proof of what has been
completed in the activity and what can be repeated with similar expected outcomes.
Interpretation of observations and results should ensue from the hypothesis being tested or the
investigation undertaken. The final interpretation should be coherent and should explain clearly how
your conclusions are reached.
Practical inquiry and application of results e.g. if results are ambiguous, you should consider your
results, and where necessary repeat the activity or design a new activity. You should consider the
results in a wider context and make suggestions or identify the activity as a scientific paradigm (an
activity that serves as a model for further work).
7
Conduct a Qualitative Test for Starch
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
8
Safety/Risks:
Labelled diagram:
Results:
Sample
Initial Colour
Final Colour
Starch Solution
Water
Conclusion:
9
Questions on Qualitative Test for Starch:
1.
State clearly the aim of this experiment.
__________________________________________________________________________________
__________________________________________________________________________________
2.
Name the three chemical elements present in starch.
__________________________________________________________________________________
3.
To what food group does starch belong?
__________________________________________________________________________________
4.
Name three foods that contain starch.
(i)
_______________________________________________________________________
(ii)
_______________________________________________________________________
(i) _____________________________________________________________________
5.
What is the function of starch in the diet?
__________________________________________________________________________________
6.
Draw a labeled diagram of the apparatus you will use in this experiment.
7.
What chemical is used to test for starch?
__________________________________________________________________________________
8.
When this chemical is added to starch, what colour change will be observed?
__________________________________________________________________________________
9.
Is heat needed?
__________________________________________________________________________________
10
10.
Suggest a control for this experiment.
__________________________________________________________________________________
11.
Why do you swirl the solutions in the test tubes?
__________________________________________________________________________________
12.
What colour change indicates a positive result?
__________________________________________________________________________________
13.
Name an enzyme in the body that breaks down starch.
__________________________________________________________________________________
14.
State where in the digestive system this enzyme acts.
__________________________________________________________________________________
15.
What is the product of this enzyme’s action?
__________________________________________________________________________________
16.
When starch is fully digested, what sub-unit is formed?
__________________________________________________________________________________
17.
Name the structure in the gut through which this sub-unit is absorbed.
__________________________________________________________________________________
18.
Name the blood vessel that connects the small intestine to the liver.
__________________________________________________________________________________
11
Conduct a Qualitative Test for a Reducing Sugar
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
12
Safety/Risks:
Labelled diagram:
Results:
Sample
Initial Colour
Final Colour
Glucose Solution
Water
Conclusion:
13
Questions on Qualitative Test for a Reducing Sugar:
1.
Give one example of
a monosaccharide ____________________________________________________________
a disaccharide _______________________________________________________________
a polysaccharide _____________________________________________________________
2. Give one example of a reducing sugar and state its function in the body
Name: ________________________________________________________________________
Function: ______________________________________________________________________
3.
What reducing sugars did you use in this experiment?
__________________________________________________________________________________
4.
What did you use as a control?
__________________________________________________________________________________
5.
What reagent did you use?
__________________________________________________________________________________
6.
Did you need to use heat and if so, how did you heat the solution?
__________________________________________________________________________________
7.
When Benedict’s reagent is added to a reducing sugar and heated, what colour change occurs?
__________________________________________________________________________________
8.
Suggest a control for this experiment.
__________________________________________________________________________________
9.
Was there a colour change in the control?
__________________________________________________________________________________
14
10.
If you used a mortar and pestle in this experiment what was its function?
__________________________________________________________________________________
__________________________________________________________________________________
11.
If sucrose was used with the reagent, what result would you expect? Explain your answer.
__________________________________________________________________________________
__________________________________________________________________________________
12.
By what process are reducing sugars made in plants?
__________________________________________________________________________________
13.
State a use for the benedicts test in the biology laboratory
__________________________________________________________________________________
How to remember this experiment!
“Pope Benedict with his sweet tooth takes a hot bath in his brick red house”
15
Conduct a Qualitative Test for Protein
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
16
Safety/Risks:
Labelled diagram:
Results:
Sample
Initial Colour
Final Colour
Protein Solution
Water
Conclusion:
17
Questions on Qualitative Test for Protein:
1.
Name the chemical elements present in a protein.
__________________________________________________________________________________
2.
Name 3 foods that contain protein.
__________________________________________________________________________________
__________________________________________________________________________________
3.
What are the products of the digestion of protein?
__________________________________________________________________________________
4.
Give one example of a structural protein and one example of a metabolic protein.
__________________________________________________________________________________
__________________________________________________________________________________
5.
State one reason that your body needs protein.
__________________________________________________________________________________
6.
What chemical(s) is used to test for protein?
__________________________________________________________________________________
7.
When this chemical(s) is added to protein, what colour change is observed?
__________________________________________________________________________________
8. Suggest a control for this experiment?
__________________________________________________________________________________
9. State 2 precautions you should consider before carrying out this experiment.
__________________________________________________________________________________
__________________________________________________________________________________
18
10. What 2 chemicals make up the biuret reagent?
_________________________________________________________________________________
11. Was heat needed for this test?
_________________________________________________________________________________
12. Name an enzyme that acts on protein in the body and the product formed.
_________________________________________________________________________________
13. Of what sub-unit are proteins made?
_________________________________________________________________________________
14. Name the infolding in the small intestine through which these sub-units are absorbed.
_________________________________________________________________________________
15. Name the blood vessel by which these sub-units are transported to the liver.
_________________________________________________________________________________
16. Excess of these sub-units are converted to _____________________by a process called
_________________________ in the liver.
17. To which group of molecules do enzymes belong?
_________________________________________
18. State one reason that your body need protein
___________________________________________________________________________________
19. Name the element, other than carbon, hydrogen and oxygen, which is always found in protein
__________________________________________________________________________________
20. Name two foods in which you found protein.
_________________________________________________________________________________
19
Conduct a Qualitative Test for Fat
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
20
Safety/Risks:
Labelled diagram:
Results:
Sample
Translucent Spot
Before Drying
After Drying
Oil
Water
Conclusion:
21
Questions on Qualitative Test for Fat:
1.
Name the 3 chemical elements present in fat.
__________________________________________________________________________________
2.
Name 3 foods that contain fat.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
3.
What are the products of the digestion of fats?
__________________________________________________________________________________
4.
Where is fat stored in animals?
__________________________________________________________________________________
5.
What will you use to test for the presence of fat?
__________________________________________________________________________________
6.
What result will indicate the presence of fat?
__________________________________________________________________________________
7.
Suggest a control in this experiment.
__________________________________________________________________________________
14.
Name and give an example of the two states of fat at room temperature.
__________________________________________________________________________________
15.
Name an enzyme that acts on fat.
_________________________________________________________________________________
16.
What are fats broken down to in the body?
__________________________________________________________________________________
22
17.
Into what structure are the digested end products absorbed?
__________________________________________________________________________________
18.
This structure is part of what system?
__________________________________________________________________________________
19.
Through what blood vessel does fat re-enter the blood stream?
__________________________________________________________________________________
20.
State a role of fat in the body.
__________________________________________________________________________________
21. In what way do fats differ from carbohydrates in terms of their elements?
__________________________________________________________________________________
22.
In what structure are phospholipids located?
__________________________________________________________________________________
23. State the difference between a lipid and a phospholipid
__________________________________________________________________________________
23
Skills for Food Tests
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to your teacher’s instructions
Fill and empty the pipette
Set up the water bath
Use the test-tube holder safely
Use the timer accurately
Label the tubes correctly
Swirl the tubes
Observe a colour change
Note the appearance of the translucent spot
Appreciate the significance of heat in the
Test for Sugar
Notice the effect of swirling
Write up the procedure
Record colour change/translucent
spot
Tabulate results
Compare with controls
Draw reasonable conclusions about foods
tested from your observations and results
Become aware of any other application(s) of
what you learned in this activity
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label the test tubes as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Food Tests
•
To quickly dry the brown paper in the fat test place it on a radiator for a minute or two.
•
Filter paper may be used instead of brown paper in the fat test.
•
When carrying tubes a test-tube holder tends to be better than a tongs.
•
When using Benedict’s reagent it is essential to use the qualitative rather than quantitative
type to obtain a brick-red colour with a reducing sugar
24
Ecology: Identify any five fauna and any five flora using simple
keys. Identify a variety of habitats within the selected ecosystem
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
(a)
To identify fauna and flora
List steps taken with reasons:
(b)
To identify a variety of habitats in the ecosystem
List steps taken with reasons:
25
Safety/Risks:
Results table:
Organism identified:
Organism identified:
Identifying feature(s):
Identifying feature(s):
Habitat:
Habitat :Organism identified
Organism identified:
Organism identified:
Identifying feature(s):
Identifying feature(s):
Habitat:
Habitat:
Organism identified:
Organism identified:
Identifying feature(s):
Identifying feature(s):
Habitat:
Habitat:
26
Organism identified:
Organism identified:
Identifying feature(s):
Identifying feature(s):
Habitat:
Habitat:
Organism identified:
Organism identified:
Identifying feature(s):
Identifying feature(s):
Habitat:
Habitat:
Organism identified:
Organism identified:
Identifying feature(s):
Identifying feature(s):
Habitat:
Habitat:
Conclusion:
27
Skills for Identifying Flora and Fauna
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to the teacher’s instructions
Use identification keys to identify flora
Use identification keys to identify fauna
Use a hand lens correctly
Handle the organisms with care
Observe a variety of habitats
Note the features of both flora and fauna
Notice adaptations of organisms
Observe the effect of using a hand lens
Write up the procedure
Draw a map/sketch of the ecosystem
Tabulate results
Draw reasonable conclusions about the flora
and fauna present in the habitat(s) observed
from your observations and results
Become aware of any other application(s) of
what you learned in this activity for examples
the use of key in a diagnosing tree to diagnose
disease
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Work in an organised and efficient manner
Leave the area as you found it
Hints for Identifying Flora and Fauna using a key:
• Although it is not on the syllabus, it is sometimes useful to have students make a dichotomous
key using objects they already know, e.g. lab equipment or photos of known animals. This
helps them to understand how a key works.
• Collect fauna using appropriate apparatus to help the identification process, e.g. a net.
• When using a dichotomous key, always read both descriptions in the couplet even if the first
one seems to be the logical one. If a choice is not clear, follow both options. If two answers are
still possible, follow both alternative paths until an answer becomes clear.
• Avoid guessing the measurements of the specimen. Use a calibrated scale. A section of a metre
stick may be photocopied onto an acetate sheet and held on a clipboard for easy access during
your fieldwork
• Hold small animals in a clear plastic con tainer, not glass.
• Use a good quality hand lens, one with a 10x magnification
28
Questions on Identifying Flora and Fauna:
1. Use the following key to identify each of these animals. Write down each letter and the animal it
represents in your answer book.
1. Jointed legs present ………………………………………….… 2
2.
3.
4.
5.
6.
Jointed legs absent ……………………………………………..….…
Three pairs of jointed legs….……………………….……….......
Four pairs of jointed legs……………………..………………...…
Body divided into segments……………………….……….......
Body not divided into segments……………………….....……
Shell present ….……………………………………………........…….
Shell absent ............................................................…...
Ring of tentacles around the mouth……….…………………
No tentacles……………………………………………………..….……
Flat body with eye spots………………………………………..….
Round body with pointed ends ………………………..………
3
Diving beetle
Water mite
Leech
4
Pond snail
5
Hydra
6
Planarian
Nematode
2. In ecological studies what is a key?
__________________________________________________________________________________
__________________________________________________________________________________
3. How is a key used?
__________________________________________________________________________________
__________________________________________________________________________________
29
4. What are the main characteristics that you used to identify plants in the habitat studied?
__________________________________________________________________________________
__________________________________________________________________________________
5. Name one animal that you identified in your ecosystem.
__________________________________________________________________________________
6.
State two features that this animal had to allow you to identify it
__________________________________________________________________________________
__________________________________________________________________________________
7.
How were you able to identify animals that you found in an ecosystem?
__________________________________________________________________________________
8. What is meant by the term fauna? ____________________________________________
9. What is meant by the term flora? _____________________________________________
30
Ecology: Identify and use various apparatus required for collection
methods in an ecological study.
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure:
1. In the tables below name the equipment that you are going to use to collect fauna from the
habitats in the ecosystem you are studying
2. Draw a sketch of the equipment
3. Describe how the equipment is used to collect the organism
4. Name the type of organism collected using the equipment
Name of equipment
Diagram
How used
•
•
•
Organism(s) collected
Name of equipment
Diagram
How used
•
•
•
Organism(s) collected
31
Name of equipment
Diagram
How used
•
•
•
Organism(s) collected
Name of equipment
Diagram
How used
•
•
•
Organism(s) collected
Name of equipment
Diagram
How used
•
•
•
Organism(s) collected
Safety/Risks:
32
Results:
Name of organism
(5 plants and 5 animals)
Habitat (where found)
in the ecosystem
A structural adaptation
you observed
Conclusion:
33
Collection apparatus
used
Skills for Collection Apparatus:
Skill
1. Following Instructions
2. Manipulation of
apparatus
Observation
3.
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to the teacher’s instructions
Identify collection apparatus appropriate to the
ecosystem you are studying
Use each piece of apparatus appropriately
Note the use of each piece of apparatus
Identify each piece of apparatus used
Identify the organisms collected
Write up the procedure
Draw diagrams of apparatus
Tabulate results
Draw reasonable conclusions about the range
of organisms in your habitat and the
suitability of equipment for collection of
organisms from your observations and results
Become aware of any other application(s) of
what you learned in this activity
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label as appropriate
Carefully return any collected fauna to where they
were found
Leave the area as you found it
Hints for Collection Apparatus:
•
•
•
•
•
•
•
•
Mark the mouthpiece on your pooter with coloured tape to avoid sucking the wrong tube
When setting pitfall traps, make sure there are no gaps between the rim of the trap and
the edge of the hole.
After collecting pitfall traps, fill in the holes with soil.
When using a beating tray, it is important not to disturb the vegetation to be
investigated until you are ready to apply the vigorous shake.
If a pitfall trap is being used for capture-recapture, bait could be used.
When using a plankton net, it is necessary to draw it through the water for a distance of
approximately 250m.
When setting small mammal traps, ensure they are stable and the chamber is sloped to
prevent water running in.
Bedding and bait should be placed in small mammal traps.
34
Questions on Collection Apparatus:
1. List 5 pieces of equipment you used to study an ecosystem
__________________________________________________________________________________
__________________________________________________________________________________
2. What is ecology?
__________________________________________________________________________________
3. What is meant by environment?
__________________________________________________________________________________
4. What is an ecosystem?
__________________________________________________________________________________
5. Can you name some ecosystems?
__________________________________________________________________________________
6. What is the biosphere?
__________________________________________________________________________________
7. What is a habitat?
_________________________________________________________________________________
8. What is a community?
__________________________________________________________________________________
9. All organisms are adapted to live successfully in their ecosystem/habitat. Adaptations can be
(a) Structural, (b) Competitive or (c) Behavioural. Distinguish between these 3 categories of
adaptations by explaining each one and name one organism and its adaptation for each category.
(a) Structural Adaptation
__________________________________________________________________________________
_________________________________________________ ________________________________
Organism name _______________________________ Adaptation _____________________
(b) Competitive Adaptation
__________________________________________________________________________________
_________________________________________________ ________________________________
Organism name _______________________________ Adaptation ____________________
(c) Behavioural Adaptation
__________________________________________________________________________________
__________________________________________________________________________________
Organism name _______________________________ Adaptation ____________________
35
Ecology: Conduct a quantitative study of plants and animals of a
sample area of the selected ecosystem (a)
Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. Identify
possible sources of error in such a study.
The syllabus requires that students carry out 1 quantitative method for 2 plants and 1
quantitative method for 2 animals
Method 1: FREQUENCY or % FREQUENCY – suitable for plants or sessile animals (e.g. limpets)
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method for PLANTS and sessile ANIMALS (e.g. limpet)
Frequency or % Frequency
List steps taken with reasons:
Labelled diagram:
36
Results: when using a frame quadrat
Organism
1
2
Frequency =
3
4
5
6
Quadrat throw
7
8
9
10
Total Frequency % Frequency
No. of quadrats containing organism
No. of quadrats thrown
If percentage frequency is required use formula:
% Frequency = Frequency x 100
Transfer your result to labelled bar chart:
Possible sources of error.
Safety/Risks:
37
Ecology: Conduct a quantitative study of plants and animals of a
sample area of the selected ecosystem (b)
Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. Identify
possible sources of error in such a study.
The syllabus requires that students carry out one quantitative method for 2 plants and one
quantitative method for 2 animals
Method 2: % Cover – suitable for ‘cover’ plants (e.g. grass) or abundant sessile animals (e.g.
barnacles)
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method for PLANTS and sessile ANIMALS (e.g. barnacle)
% Cover
List steps taken with reasons:
Labelled diagram:
38
Results: when using a 25-point gridded quadrat
Quadrat throw
Organism
Name
e.g. Grass
1
2
3
4
5
% Cover =
6
7
8
9
10
Total no.
of Hits Total Points % Cover
250
250
No. of hits
×100
Τotal no. of po int s
Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode.
A pie chart is a good way to display these results
Possible sources of error.
Safety/Risks:
39
Ecology: Conduct a quantitative study of plants and animals of a
sample area of the selected ecosystem (c)
Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. Identify
possible sources of error in such a study.
The syllabus requires that students carry out any one quantitative method for 2 plants and any
one quantitative method for 2 animals.
Method 3: Capture/recapture method. Suitable for some animals e.g. snails
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method for animals
Capture/recapture
List steps taken with reasons:
40
Labelled diagram:
Results for Capture/Recapture method:
Name of animal
Method of capture
Method of marking
Number captured and marked – first time
Number of animals captured – second time
Number of the recaptures i.e. those that were
marked when caught at the second time
Population =
Number caught 1st time x number caught 2nd time
Number that were recaptured (i.e. marked)
Population range can be measure by repeating the activity a few more times. The population range
is between the lowest and the highest number calculated
Possible sources of error.
Safety/Risks:
41
Skills for Quantitative Studies:
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to the teacher’s instructions
Identify apparatus appropriate to the ecosystem
you are studying
Use each piece of apparatus appropriately for
estimating numbers of flora and fauna
Observe the distribution of organisms in an
ecosystem
Observe a variety of habitats within an
ecosystem
Note the use of each piece of apparatus
Identify each piece of apparatus used
Identify the different species present at
various times
Write up the procedure
Draw a diagram if necessary
Tabulate results
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label apparatus as appropriate
Ensure not to mark any fauna so that they will
become more obvious to prey
Leave the area as you found it
Hints for Quantitative Studies:
•
Mark off the sample area by using poles with string or flags or by other visible markers e.g. trees,
paths, rocks, etc.
•
Throw a small object over your shoulder to select a random sample point.
•
Place the quadrat down carefully so that the animals are not disturbed allowing you to count
them.
•
Pour water onto the ground in the quadrat to get the slugs and earthworms to come to the surface
where they can be seen and counted.
•
In the capture-recapture technique, use poster paints to mark animals, as this paint will wear off
after a short time. This will reduce their chance of being preyed upon.
42
Questions on Quantitative Studies in Ecology:
1. Distinguish between a qualitative and quantitative ecological survey.
__________________________________________________________________________________
__________________________________________________________________________________
2. What is meant by percentage cover in an ecological survey of an ecosystem?
__________________________________________________________________________________
__________________________________________________________________________________
3. In the case of a named plant describe how you estimated the percentage cover of this plant in
the ecosystem that you studied.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
4. Describe how you recorded your results of the above experiment
_________________________________________________________________________________
_________________________________________________________________________________
5. Suggest a possible source of error in your study
_________________________________________________________________________________
_________________________________________________________________________________
6. What is a quadrat?
__________________________________________________________________________________
7. Why were the quadrat sites chosen randomly?
__________________________________________________________________________________
__________________________________________________________________________________
8. How did you ensure that the quadrat sites were chosen randomly?
__________________________________________________________________________________
__________________________________________________________________________________
43
9. Why would you use ten quadrat throws instead of one?
__________________________________________________________________________________
__________________________________________________________________________________
10. What is the frequency of clover if it is present in 45 out of 50 randomly thrown quadrats?
__________________________________________________________________________________
__________________________________________________________________________________
11. When carrying out a quantitative study why might you use a line transect instead of a quadrat?
__________________________________________________________________________________
__________________________________________________________________________________
12. Why is the quadrat method not always suitable for estimating the numbers of animals in a
habitat?
__________________________________________________________________________________
__________________________________________________________________________________
44
Investigate any three abiotic factors present in the selected
ecosystem, as listed in syllabus.
Relate results to choice of habitat selected by each organism identified in your ecological study.
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
Abiotic Factor 1 – Name:
List steps taken with reasons:
Abiotic Factor 2 – Name:
List steps taken with reasons:
45
Abiotic Factor 3 – Name:
List steps taken with reasons:
Safety/Risks:
Labelled diagrams of apparatus:
Name:
Name:
Name:
46
Results chart – complete for at least 3 factors appropriate to your selected ecosystem
Factor
Apparatus or method used
Result (include units)
Soil temperature range
Air temperature range
Water temperature range
Soil pH
Average wind speed
Light Intensity
% air in soil
% water in soil
Results related to choice of habitat selected by identified organisms
Organism
Name
Daisy
Habitat
Open grassland area
Abiotic Factor affecting suitability for organism
Daisy favours high light intensity habitat
Conclusion:
47
Skills for Abiotic Factors:
Skill
1. Following Instructions
2. Manipulation of
apparatus
3. Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to the teacher’s instructions
Use each piece of apparatus appropriately
Observe the distribution of organisms in an
ecosystem
Observe a variety of habitats within an
ecosystem
Note the link between the abiotic factors and
the organism’s choice of habitat
Write up the procedure
Draw a diagram if necessary
Tabulate the result
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label diagrams as appropriate
Work in an organised and efficient manner
Leave the area as you found it
Hints:
•
•
If you have data logging equipment use it to measure salinity, dissolved oxygen, pH and
temperature.
Relate the distribution of the organisms to the abiotic factors
48
Question on Abiotic Factors:
1. What is meant by the term Abiotic factor?
___________________________________________________________________________
___________________________________________________________________________
2. How would you investigate a named abiotic factor other than temperature or pH?
Abiotic Factor _______________________________________________________________
How Investigated
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
3. In relation to the ecosystem you have studied describe how two named organisms are
adapted to the abiotic factors present?
Organism 1 _________________________________________________________________________
How Adapted
__________________________________________________________________________________
Organism 2 ________________________________________________________________________
How Adapted
__________________________________________________________________________________
__________________________________________________________________________________
4. Referring to the abiotic factors in the ecosystem list any three and the scientific units
used to measure the quantity
Abiotic Factor
Units
49
5. When measuring some factors it is important to measure them over a period of time and
get a range of measurements. Name 2 abiotic factors where a range of measurements should
be made
(a) ________________________
(b)________________________
Why do you think that this is important? ________________________________________________
_________________________________________________________________________________
6. When measuring some factors it is important to measure them over a period of time and
get an average reading. Name 2 abiotic factors where the range of readings should be taken
(a) ____________________________
(b)________________________
Why do you think that this is important? ________________________________________________
__________________________________________________________________________________
7. How might the wind speed affect an ecosystem and what grows there? _______________
__________________________________________________________________________________
8. How might the light intensity affect an ecosystem and what grows there?______________
__________________________________________________________________________________
50
Be familiar with and use the light microscope
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
51
Safety/Risks:
Labelled diagram:
Results:
Formula for Magnification: Magnification of the Objective lens x Magnification of the Eyepiece lens
Eyepiece Lens
X1
X4
X10
Objective Lens
X4
X 15
Total Magnification
1000
Conclusion:
52
Skills for Using the Microscope
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to the teacher’s instructions
Provide a light source
Rotate nosepiece so that the low power
objective lens is being used first
Place the slide on the stage
Use the stage clips to hold the slide
Use the coarse adjustment wheel
Use the iris diaphragm
Use the fine adjustment wheel
Use the high power objective lens
Refocus using the fine adjustment wheel
See a clear image
Appreciate the importance of the correct
placement of the slide
Notice the effect of magnification
See the effect of adjusting the iris diaphragm
Appreciate the use of the coarse adjustment
wheel
Appreciate the use of the fine adjustment
wheel
Write up the procedure
Name each piece of the microscope
Draw labelled diagrams of your observations
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
using the microscope to view other cell types
Exercise caution for your personal safety and
for the safety of others
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for using the microscope:
• Clean the lenses of the microscope using lens tissue
• To locate small objects e.g. single cells, reduce the light intensity by closing the iris
diaphragm and traverse the slide methodically
• A common mistake is to have too much light coming through the specimen particularly
when viewing under low power. Opening or closing the iris diaphragm will vary the light
intensity.
53
Questions on using the Microscope:
1.
Name the parts labeled 1- 9 on the diagram of the light microscope and give the function for
each part :
Name
Function
1
2
3
4
5
6
7
8
9
2.
What apparatus was needed for this experiment?
__________________________________________________________________________________
__________________________________________________________________________________
3.
Name one other type of microscope:
__________________________________________________________________________________
54
4.
State one advantage of the microscope you have named:
__________________________________________________________________________________
__________________________________________________________________________________
5.
When using the light microscope, which objective lens will you rotate into place first?
_________________________________________________________________________________
6.
If you think that more or less light is required to view the slide what part of the microscope
will you adjust?
________________________________________________________________________________
7.
How do you change the magnification?
__________________________________________________________________________________
8.
How do you calculate the total magnification?
__________________________________________________________________________________
9.
State one precautions you should consider before carrying out this experiment: Note:
precautions are steps that will help the experiment work well. They are not safety risks.) One
example is given – give another.
Precaution: Clean the lens with lens tissue before use
a) ______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
55
Prepare and examine one animal cell, unstained and stained, using
the light microscope (X100, X400)
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
56
Safety/Risks:
Labelled diagram:
Results:
Draw a labelled diagram of what you saw under the microscope:
Unstained Cheek Cell Under Low Power
Unstained Cheek Cell Under High Power
57
Stained Cheek Cell Under Low Power
Stained Cheek Cell Under High Power
Conclusion:
58
Skills for Animal Cells
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Use the light microscope effectively
Use the inoculating loop to gather cheek cells
Transfer the sample to the slide
Cover the sample with water
Apply the cover slip
Apply the stain from the dropper
Gently wash excess stain off the sample
Locate cells
View cells under different magnification
Differentiate between cells and debris
Appreciate the limitation of the unstained
preparation
Appreciate the value of the stained
preparation
Write up the procedure
Name each pieceof apparatus used
Draw a label led diagram
Draw reasonable conclusions from your
observations and results
6. Application
Become aware of any other application(s) of
what you learned in this activity for example
using other stains to view cell parts
7. Organisation
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints:
•
•
Gloves should be worn when using stains.
Place the slides on a rack over a small tray when staining to avoid spillages on the
desk.
•
Ethanoic acid (10%) may be used on the unstained animal cell to highlight the
nucleus. Ethanoic acid is not a stain.
59
Questions on Animal Cells:
1. Why did you use methylene blue when examining cheek cells under the microscope?
__________________________________________________________________________________
__________________________________________________________________________________
2. Outline the differences between a plant and animal cell
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
3. State one precaution that you should consider before carrying out this experiment:
(ii)________________________________________________________________________
________________________________________________________________________
4. What is a tissue?
__________________________________________________________________________________
__________________________________________________________________________________
5. In the space provided, draw a typical animal cell, and label the following parts:
-Cell membrane
-Cytoplasm
-Nucleus
-Nuclear pores
-Ribosome
-Mitochondrion
-DNA
60
6. Describe briefly how you will obtain a sample of human cheek cells
__________________________________________________________________________________
__________________________________________________________________________________
7. Why is a mounted needle used?
__________________________________________________________________________________
8. Outline how you applied the stain to the slide
__________________________________________________________________________________
__________________________________________________________________________________
9. Why is a cover slip placed on the slide?
__________________________________________________________________________________
__________________________________________________________________________________
61
Prepare and examine one plant cell, unstained and stained, using
the light microscope (X100, X400)
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
62
Safety/Risks:
Labelled diagram:
Results:
Draw a labelled diagram of what you saw under the microscope:
Unstained Plant Cell Under Low Power
Unstained Plant Cell Under High Power
63
Stained Plant Cell Under Low Power
Stained Plant Cell Under High Power
Conclusion:
64
Skills for Plant Cells
Skill
1. Following
Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Use the light microscope
Remove some of the onion epidermis
Transfer small pieces of the epidermis to
water in the petri dish
Put a piece of the epidermis in a drop of
water on the slide
Apply the cover slip
Draw the iodine across under the cover slip,
using the filter paper
Gently wash excess stain off the sample
Locate the epidermis between the fleshy
leaves of the onion
Locate cells under the microscope
View cells under different magnification
Appreciate the limitations of the unstained
preparation
Appreciate the value of a stained preparation
Write up the procedure
Name each pieceof apparatus used
Draw a label led diagram
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
using different magnifications and microscope
types to identify different organelles and cell
processes such as mitosis
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints:
•
•
Gloves should be worn when using stains.
Place the slides on a rack over a small tray when staining to avoid spillages on the
desk.
•
•
Cut small pieces of the onion epidermis while still on the onion.
Multiple nucleoli (two) may be seen in onion nuclei.
65
Questions on Plant Cells:
1.
Why are stains often used when examining cells under the microscope?
__________________________________________________________________________________
__________________________________________________________________________________
2.
State one precaution you should consider before carrying out this experiment:
(i) ___________________________________________________________________________
______________________________________________________________________________
3. What was the source of the plant cells used in this experiment?
__________________________________________________________________________________
4. State why it is necessary to store the sample in water until you are ready to proceed:
__________________________________________________________________________________
5.
Complete the following table:
Name:
Function:
Absorbent paper
Iodine
6. Describe briefly how you will obtain a sample of plant cells.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
7. Why do you place a drop of water on the slide before adding the sample on it?
__________________________________________________________________________________
__________________________________________________________________________________
8. Describe how you place the cover slip on the slide.
__________________________________________________________________________________
__________________________________________________________________________________
9.
Outline how you use the microscope to examine the cells.
__________________________________________________________________________________
__________________________________________________________________________________
66
__________________________________________________________________________________
__________________________________________________________________________________
10. Which objective lens will you use first to view the cells?
__________________________________________________________________________________
11. What holds the slide in place on the stage?
__________________________________________________________________________________
12. State two features of these cells that indicate that these are plant cells
__________________________________________________________________________________
13. How did you focus the microscope correctly to view the sample?
__________________________________________________________________________________
67
Investigate the effect of pH on the rate of enzyme activity
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
68
Safety/Risks:
Labelled Diagram
Results:
pH of Buffer Solution
Initial Volume (cm3)
Final Volume (cm3)
Conclusion:
69
Volume of Foam (cm3)
Plot a graph of the rate of Enzyme Activity (i.e. the volume of foam after a stated time) on the Y
axis against the pH on the x axis. Label the axes.
70
Skills for pH of Enzymes
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Maintain constant temperature (25 °C) in the
beaker
Obtain enzyme extract
Use the syringe correctly
Use and read the graduated cylinder correctly
Measure pH correctly
Use the timer
Use the electronic balance
Appreciate the use of washing-up liquid
Note the evolution of bubbles in the mixture
Note the rise of foam in the cylinders
Note the colours on the pH papers before and
after dipping in solutions if using
Write up the procedure
Record the volume of foam per unit time
Tabulate the results
Record the pH in each cylinder
Draw a graph with labelled axes
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
in our digestive systems
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for pH for enzymes:
• Besides celery there are many other good sources of catalase. Liver is the best source but
radish and potato are also good. These can be used chopped. To prepare celery extract,
chop 3 stalks and macerate them in a blender in 100 cm3 of distilled water. Filter through
coffee filter. If using liver, macerate 5 g in 100 cm3 of distilled water and strain through a
household sieve. Use 1 cm3 of these extracts in each cylinder. Increase this volume if activity
is low.
• Enzyme preparations lose activity very quickly. Therefore, the enzyme extract must be
prepared immediately before use.
• If enzyme activity is high, e.g. when using liver, use larger cylinders.
71
Questions on the effect of pH on enzyme activity:
1.
What is an enzyme?
__________________________________________________________________________________
__________________________________________________________________________________
2.
Name the enzyme you used and give its source
__________________________________________________________________________________
__________________________________________________________________________________
3. Name the substrate for this enzyme
___________________________________________________________________________________
4.
List 3 factors that affect enzyme activity
___________________________________________________________________________________
5.
Sketch a graph to show the effect of pH on enzyme activity
6. How would the graph differ for a stomach enzyme?
___________________________________________________________________________________
___________________________________________________________________________________
7. What factors are kept constant during this experiment?
___________________________________________________________________________________
___________________________________________________________________________________
72
8. How is each factor is kept constant?
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
9. How is the rate of enzyme activity measured?
___________________________________________________________________________________
___________________________________________________________________________________
10. How did you know at which pH the enzyme worked best?
___________________________________________________________________________________
___________________________________________________________________________________
11. What is the optimum pH for the enzyme you used?
_________________________________________________________________________________
12. Enzymes are specific. What is meant by specificity of an enzyme?
_________________________________________________________________________________
_________________________________________________________________________________
13. Explain the biological basis for adding enzymes added to some washing powder
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
73
Investigate the effect of temperature on the rate of enzyme activity
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
74
Safety/Risks:
Labelled diagram:
Results:
Temperature (oC)
Initial Volume (cm3)
Final Volume (cm3)
Conclusion:
75
Volume of Foam (cm3)
Plot a graph of the rate of Enzyme Activity (i.e. the volume of foam after a stated time) on the Y
axis against the temperature on the X axis. Label the axes.
76
Skills for Effect of Temperature of Enzymes
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures before
starting
Follow step by step method
Listen to the teacher’s instructions
Prepare the enzyme source
Use the syringe, thermometer, graduated cylinder
correctly
Use the electronic balance accurately
Set up and maintain the water baths
Use the test-tube holder
Use the timer
Appreciate the use of washing-up liquid
Note the evolution of bubbles in the mixture
Note the rise of foam in the cylinders
Write up the procedure
Record the temperature each time
Record the volume of foam
Tabulate the results
Draw a graph with labelled axes
Draw reasonable conclusions from your observations
and results
6. Application
Become aware of any other application(s) of what you
learned in this activity for example in baking
7. Organisation
Exercise caution for your personal safety and for the
safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Effect of Temperature of Enzymes
•
A more accurate value for optimum temperature may be obtained by carrying out
the investigation at more than the minimum five temperatures.
•
Enzyme preparations lose activity very quickly. Therefore, the enzyme extract must
be prepared immediately before use.
•
Liver is the best source of catalase but celery, radish and potato are also good.
•
If activity is high, e.g. when using liver, use larger cylinders.
77
Questions on the effect on temperature on enzyme activity:
1. What is an enzyme? _______________________________________________________________
__________________________________________________________________________________
2. Name the enzyme you used and give its source.
__________________________________________________________________________________
__________________________________________________________________________________
3. Name the substrate for this enzyme.
__________________________________________________________________________________
4. List 3 factors that affect enzyme activity.
__________________________________________________________________________________
__________________________________________________________________________________
5. Sketch a graph to show the effect of temperature on enzyme activity.
6. What factors are kept constant during this experiment?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
78
7. How is each factor kept constant?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
8. How is the rate of enzyme activity measured?
__________________________________________________________________________________
__________________________________________________________________________________
9. How did you know at which temperature the enzyme worked best ?
__________________________________________________________________________________
__________________________________________________________________________________
10. What is the optimum temperature range for the enzyme you used?
__________________________________________________________________________________
79
Investigate the effect of heat denaturation on the activity of an
enzyme
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
80
Safety/Risks:
Labelled Diagram
Results:
Boiled Enzyme
Height of Foam
Enzyme Active
Yes/No
Conclusion:
81
Unboiled Enzyme
Skills for Heat Denaturation of Enzymes
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Prepare the enzyme source
Use the syringe, thermometer, graduated
cylinder correctly
Use the electronic balance accurately
Set up and maintain the water baths
Use the test-tube holder
Use the timer
Note the presence or absence of foam
Write up the procedure
Record the temperature each time
Record the volume of foam
Tabulate the results
Draw a graph with labelled axes
Draw reasonable conclusions from your
observations and results
6. Application
Become aware of any other application(s) of
what you learned in this activity for example
different temperatures required for plant and
animal enzymes to work
7. Organisation
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label diagrams as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Denaturation
•
Enzyme preparations lose activity very quickly. Therefore, the enzyme extract must
be prepared immediately before use.
•
Liver is the best source of catalase but celery, radish and potato are also good.
•
If activity is high, e.g. when using liver, use larger cylinders.
82
Questions on heat denaturation and enzymes:
14.
What is an enzyme?
__________________________________________________________________________________
__________________________________________________________________________________
15.
Name the enzyme you used and give its source
___________________________________________________________________________
___________________________________________________________________________
16. Name the substrate for this enzyme
__________________________________________________________________________________
17. List 3 factors that affect enzyme activity
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
18. What factors are kept constant during this experiment?
__________________________________________________________________________________
__________________________________________________________________________________
19. How is each factor kept constant?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
20. How is the rate of enzyme activity measured?
__________________________________________________________________________________
___________________________________________________________________________
21.
Explain the biological basis for adding enzymes to some washing powders.
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
22. Give a detailed account of how enzymes work, referring in your answer to their
specificity.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
83
Labelled Diagram
23. During an experiment of temperature v rate of enzyme activity, the following results
were obtained.
Temp. oC
10
20
30
40
50
60
70
Rate of reaction ml/min.
3
17
34
29
10
0
0
(i) Draw a graph for the above data on the graph paper below
(ii) What is the optimum temperature for the enzyme? __________________________________
(iii) Estimate, from your graph, the rate of reaction at 26OC. _______________________________
(iv)Estimate, from your graph, the temperature that yields a rate of 30ml/min of product. ______
Graph of temperature v rate of enzyme activity
84
Prepare one enzyme immobilisation and examine its application
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
A: Preparing the Immobilised Enzyme
List steps taken with reasons:
B: Application (Using the Immobilised Enzyme)
List steps taken with reasons:
85
Safety/Risks:
Labelled diagram:
Results:
Free Enzyme
Time Taken for product to appear
Turbidity of Solution
(Is it cloudy or clear?)
Conclusion:
86
Immobilised Enzyme
Skills for Enzyme Immobilisation:
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures before starting
Follow step by step method
Listen to the teacher’s instructions
Use the balance and time
Use a graduated cylinder to measure
volumes
Prepare solutions and mixtures
Draw the mixture of alginate solution and yeast
suspension into the syringe
Release the mixture drop by drop into the
calcium chloride solution
Transfer the beads to the separating funnel
Filter and rinse the beads with distilled water
Set up the separating funnels
Use a thermometer and a funnel
Use glucose test strips to test for glucose
Note the clarity of both sucrose solutions
See beads forming
Observe any colour change using glucose test strips
Compare the turbidity of both end products
Write up the procedure
Draw a label led diagram
Tabulate the results
Record the time
Draw reasonable conclusions from your observations
and results
6. Application
Become aware of any other application(s) of what you
learned in this activity for example in biotechnology
7. Organisation
Exercise caution for your personal safety and for the
safety of others
Work as part of a group or team
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Enzyme Immobilisation
•
Sodium alginate solution is best prepared by adding the powder to agitated water, rather
than vice versa to avoid the formation of clumps.
•
To avoid beads blocking the separating funnel, a plastic straw may be inserted into the
funnel before adding the beads.
•
Only use yeast which does not contain calcium sulphate.
87
Question on Enzyme Immobilisation:
1.
What is meant by an immobilised enzyme?
__________________________________________________________________________________
__________________________________________________________________________________
2.
Name one way that enzymes can be immobilised.
__________________________________________________________________________________
__________________________________________________________________________________
3.
List the 3 chemicals / solutions you used in the experiment and explain the purpose of each.
(i)__________________________________________________________________________
(ii)_________________________________________________________________________
(iii)_________________________________________________________________________
4.
Name the enzyme used and its source. ___________________________________________
5.
What is the substrate of this enzyme? ____________________________________________
6.
Name the product ____________________________________________________________
7.
How did you test for the product? State any colour change involved.
__________________________________________________________________________________
8.
Give two advantages of using immobilised yeast cells in the production of alcohol.
(i)__________________________________________________________________________
(ii)_________________________________________________________________________
9.
What term best describes the shape of an enzyme?
___________________________________________________________________________
10.
Lactose free milk is produced using immobilised enzymes. Name the substrate in this case.
__________________________________________________________________________________
88
Conduct any activity to demonstrate osmosis
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
89
Safety/Risks:
Labelled diagram:
Results:
Tube contents
Turgidity at
start
Turgidity after
test period
Sucrose solution
Distilled
water
Conclusion:
90
Mass at start (g)
Mass after test
period (g)
Skills for Osmosis
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Soften the tubing in water
Tie leak-proof knots
Wash off excess sucrose
Use the electronic balance
Suspend the tubes from the rods
Observe the appearance of the tubes at the
start
Observe the appearance of the tubes at the
end of the test period
Write up the procedure
Tabulate results
Draw reasonable conclusions from your
observations and results
6. Application
Become aware of any other application(s) of
what you learned in this activity
7. Organisation
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Osmosis:
•
•
•
•
•
Use visking tubing that is about 2 cm wide.
Treacle or golden syrup could be used instead of the 80% sucrose solution.
If using treacle or golden syrup, heat it in a beaker in a hot water bath to
decrease its viscosity. This makes it easier to add to the visking tubing bag.
Syringes could be used to fill the dialysis tubing bags.
Make sure to wash any sucrose solution off the knots.
91
Questions on Osmosis:
1. Define osmosis.
__________________________________________________________________________________
__________________________________________________________________________________
2. Define the term diffusion.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
3. Give an example of osmosis in plants
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
4. Suggest a control for this experiment.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
5. Suggest a reason for using distilled water rather than tap water.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
6.
Where was the highest water concentration in your experimental set-up?
__________________________________________________________________________________
__________________________________________________________________________________
7. What represents a semi-permeable membrane?
__________________________________________________________________________________
__________________________________________________________________________________
92
8.
Explain what is meant by semi-permeable membrane?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
9. Where was the highest solute concentration in your experimental set-up?
__________________________________________________________________________________
__________________________________________________________________________________
10. Osmosis is a passive process. Explain.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
11. Which substance moves through the cell by osmosis?
__________________________________________________________________________________
12. Water enters the outermost cells of the root by osmosis. What does this tell you about the cell
sap of these outermost cells?
__________________________________________________________________________________
__________________________________________________________________________________
13.
Osmosis has been described as a special case of diffusion. Explain why
__________________________________________________________________________________
__________________________________________________________________________________
93
Investigate the influence of light intensity on the rate of
photosynthesis
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
94
Safety/Risks:
Labelled diagram:
95
Results:
Distance from
Light Intensity
Trial 1
Trial 2
Average
light source
=
(No. of
(No. of
(No. of
bubbles/
bubbles /
bubbles /
minute)
minute)
minute)
(cm)
10000/
distance
2
96
Plot a graph of Light Intensity (x axis) against Rate of Photosynthesis i.e. the number of bubbles
produced per minute(y axis)
Conclusion:
97
Skills for Photosynthesis
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Carefully use the scissors to cut the end of
the plant
Place the plant in the boiling tube, cut end
pointing upwards
Use the metre stick to measure distances
of plant from light source
Use the thermometer and the timer
Use the light meter if you are using one
After allowing the plant to adjust, observe a
steady stream of bubbles
Observe the number of bubbles being
released per minute at each distance
Write up the procedure
Record the distance of the plant from the
light source
Record the number of bubbles being given off
per minute at each distance
Record the average number of bubbles
being given off per minute at each of the
given distances
Record the light intensity or 1/d2
Draw a graph with labelled axis
Draw reasonable conclusions from your
observations and results
6. Application
Become aware of any other application(s) of
what you learned in this activity
7. Organisation
Exercise caution for your personal safety and
for the safety of others
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Photosynthesis
• Use fresh elodea. Try out a few different sprigs of Elodea to see which one is bubbling best
and then use this one for the investigation.
• Use a very bright light.
• If the bubbles stop, or do not start, cut the stem again and lightly crush between your
fingers.
• Keep the pondweed down at the bottom of the boiling tube. If the pondweed tends to
float, it can be weighed down with a paper clip.
98
Questions on Photosynthesis:
1. Give a balanced chemical equation for photosynthesis.
_______________________________________________________________________________
2. Complete the following table:
Requirement:
Source:
Light
Carbon dioxide
Water
3.
Where in the cell does photosynthesis occur?
__________________________________________________________________________________
4. The factors that affect the rate of photosynthesis include light intensity, temperature and
carbon dioxide concentration. In this investigation which factor will you vary, and how will you
vary it?
Factor:
__________________________________________________________________________________
How:
_________________________________________________________________________________
5. Which factors will you keep constant and how will you keep each of these constant?
Factor:
___________________________________________________________________________
How:
___________________________________________________________________________
Factor:
__________________________________________________________________________
How:
___________________________________________________________________________
6. How will you measure the light intensity?
__________________________________________________________________________________
99
7.
Name the plant that you will use in this investigation.
__________________________________________________________________________________
8. Why will you use this plant instead of a land plant?
__________________________________________________________________________________
9. How did you prepare this plant before the experiment?
__________________________________________________________________________________
__________________________________________________________________________________
10. How will you measure the rate of photosynthesis?
__________________________________________________________________________________
11. Why will you place the plant in the water with the cut end of the stem pointing upwards?
_________________________________________________________________________________
12. Each time the light intensity is varied, the rate of photosynthesis cannot be measured
immediately. Why?
_________________________________________________________________________________
_________________________________________________________________________________
13. Explain how you calculated the rate of photosynthesis.
_________________________________________________________________________________
_________________________________________________________________________________
14. Is the experiment kept at a set temperature? Explain.
__________________________________________________________________________________
__________________________________________________________________________________
15. Suggest a way of keeping the plant at the bottom of a test tube during the investigation.
Why is it helpful to do this?
__________________________________________________________________________________
__________________________________________________________________________________
16. If the temperature of the water bath was increased to 45ᵒCelcius. Photosynthesis
would stop. Explain
__________________________________________________________________________________
__________________________________________________________________________________
100
Prepare and show the production of alcohol by Yeast
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method: To produce alcohol using yeast
List steps taken with reasons:
101
Safety/Risks:
Labelled diagram:
Procedure/Method: To show the presence of alcohol
List steps taken with reasons:
102
Results:
Flask
Original Colour of
Filtrate
Final Colour of Filtrate
Yeast and Glucose
Solution
Control ( no yeast)
Conclusion:
103
Colour Changes
Skills for Production of Alcohol by Yeast
Skill
1. Following
Instructions
2. Manipulation
of apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Use the graduated cylinder and syringe
Use the electronic balance
Attach the fermentation locks to the
conical flasks
Filter the suspension
Set and maintain the water bath
Use the timer
Observe bubbles of carbon dioxide being
liberated
Observe the effect of filtering
Observe colour changes
Observe the presence/absence of yellow
crystals
Write up the procedure
Draw a label led diagram
Record any colour changes
Record the presence/absence of yellow
crystals
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
its use in the brewing industry
7. Organisation
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label diagrams as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for production of alcohol by yeast
•
•
•
•
•
Immobilised yeast may be used instead of dried yeast - this eliminates the need to filter.
In the iodoform test - Use commercial bleach and add sodium hydroxide if necessary.
Use pure ethanol to observe positive result in the iodoform test.
Use a cork borer when inserting tubing into bungs.
Using long necked conical flasks and setting the incubator at 25 °C would help to prevent
overflow during fermentation.
•
A Bunsen valve can be used instead of a fermentation lock during fermentation.
104
Questions on Production of Alcohol by Yeast:
1. Yeasts are eukaryotic organisms. What does this mean?
__________________________________________________________________________________
2. To which kingdom does yeast belong? _______________________________________________
3. Yeast cells produce ethanol in a process called: _________________________________________
4. Is this process affected by temperature? ______________________________________________
5. Name a substance that yeast can use to make ethanol. _________________________________
6.
What is the purpose of the glucose in this experiment?
__________________________________________________________________________________
7. What is the purpose of the yeast in this experiment?
_________________________________________________________________________________
_________________________________________________________________________________
8. At what temperature will the flasks be incubated at? ___________________________________
Give a reason for your answer.
__________________________________________________________________________________
__________________________________________________________________________________
9. State one advantage of using immobilised yeast in this experiment.
_________________________________________________________________________________
10.What substance, other than ethanol, is produced during fermentation?
_________________________________________________________________________________
11. How could you test for carbon dioxide produced during fermentation?
__________________________________________________________________________________
12.Describe the control that you used in this experiment.
__________________________________________________________________________________
__________________________________________________________________________________
105
13.Explain the purpose of a control in a scientific experiment.
__________________________________________________________________________________
__________________________________________________________________________________
14.How did you know when fermentation was finished?
_________________________________________________________________________________
_________________________________________________________________________________
15. What chemical(s) did you use to test for the presence of alcohol?
_________________________________________________________________________________
16. Was heat needed in the experiment to test for alcohol?
__________________________________________________________________________________
17. State the colour changes that occurred when you tested for alcohol, if any:
_________________________________________________________________________________
18. Write a word equation for:
Anaerobic respiration in animals:
__________________________________________________________________________________
Anaerobic respiration in yeast:
__________________________________________________________________________________
19. Bioprocessing is often carried out using immobilised cells. Explain the underlined terms.
__________________________________________________________________________________
__________________________________________________________________________________
106
Isolate DNA from a plant tissue
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
107
Safety/Risks:
108
Labelled diagram:
Results:
Conclusion:
Note: Other fruits and vegetables can be used instead of an onion. Kiwis, strawberries are good.
Pineapple juice is a good source of protease.
109
Skills for Isolating DNA
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Hints for Isolating DNA
•
•
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Use the electronic balance
Use the water bath, thermometer and timer
Use the blender for the correct length of
time
Filter the mixture into a clean beaker
Add the correct amount of protease to the
filtrate
Trickle the ethanol down the side of the boiling
tube
Draw out the DNA
Accurately read the temperature of the water
bath
Observe two distinct layers of liquid after
the addition of the alcohol
Notice a change in viscosity at the
interface of the two liquids
Notice cloudy matter appearing at the
interface of the two liquids
Observe the appearance of the DNA
Write up the procedure
Record the result
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
the use of DNA analysis in forensics and
epigenetics
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Work in an organised and efficient manner
Clean up after the practical activity
Some alternatives to onions are: tomatoes, peas, peaches, nectarines and kiwi fruits.
Use a cheap brand of washing-up liquid. However, it is important not to use the
bactericidal washing-up liquid as this causes the breakdown of DNA.
•
It is vital to blend for no more than three seconds. If the DNA appears fluffy, it was sheared
in the extraction process. It should appear as thin threads.
•
•
•
Industrial methylated spirits may be used as a cheaper alternative to ethanol.
If the DNA remains at the interface, place the boiling tube back into the ice bath.
Other sources of protease include fresh pineapple juice and contact lens solution
110
Questions on DNA:
1.
What plant tissue did you use during this experiment? _________________________________
2.
Where in a cell is DNA found? _____________________________________________________
3.
In the above experiment, particular substances / methods were used to assist in the
isolation of the DNA. Give a reason for each of the following:
Substance/Method
Reason
Salt
Washing-up liquid
Chopping the plant
material
60 degree water bath
Ice cold water bath
4.
(i) Why is a blender used?
________________________________________________________________________________
________________________________________________________________________________
(ii)
Why is it used for only 3 seconds?
__________________________________________________________________________________
__________________________________________________________________________________
5.
Why is a coffee filter is used during the process instead of conventional filter paper?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
6.Why is protease used in this experiment?
__________________________________________________________________________________
__________________________________________________________________________________
111
7
The mixture was then filtered. After filtration, where was the DNA of your plant
tissue to be found?
__________________________________________________________________________________
__________________________________________________________________________________
8 How did you make the DNA visible?
__________________________________________________________________________________
9
What requirement is needed for the ethanol to work?
__________________________________________________________________________________
10
Describe how you removed the DNA from the test tube.
_________________________________________________________________________________
11 Explain each of the following terms in relation to DNA.
(i)
Replication
__________________________________________________________________________________
__________________________________________________________________________________
(ii) Transcription
__________________________________________________________________________________
__________________________________________________________________________________
12
How are the two strands of a DNA molecule joined together?
_________________________________________________________________________________
13
What is ‘junk’ DNA?
__________________________________________________________________________________
112
Investigate the growth of leaf yeast using agar plates and controls
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
113
Safety/Risks:
Labelled diagram:
Results:
Agar plate
Appearance of colonies
Control
Plate with leaves
114
Draw the appearance of the dishes after 3 days
Experimental Dish
Control Dish
Conclusion:
115
Skills for Leaf Yeasts
Skill
1.
2. Following Instructions
3. Manipulation of
apparatus
Observation
4.
5. Recording
6. Interpretation
7. Application
8. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow your step by step method
Listen to the teacher’s instructions
Label the plates
Swab the bench
Use the borer
Sterilise the forceps and the cork borer
Smear the petroleum jelly on the lid
Seal the plates
Invert and reinvert plates
Use the thermometer and the incubator
Observe the appearance of the colonies if
present
Observe any differences between the
experiment and the control plates
Write up the procedure
Record the appearance of the experiment
plate
Record the appearance of the control plate
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
growing colonies of other fungi
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Leaf Yeast Growth:
• Leaves from common ash, lilac, sycamore, red alder or hawthorn are generally suitable for
use in this investigation. Ash leaves are particularly suitable.
• Take leaves from the base of long shoots as these are the older leaves and have been on
the tree since spring and the yeasts have had time to colonise and grow.
• After collecting the leaves keep them in a rigid container e.g. a plastic box, to prevent
the leaves being crushed and the leaf yeasts from being rubbed off.
•
Take care not to get petroleum jelly on the side of the leaf discs from which the spores
are to be collected.
• Leaves can be frozen in September and used at a later date
116
Questions on Leaf Yeast:
1. Name the plant you used during this experiment.
__________________________________________________________________________________
2. To which kingdom do yeasts belong?
__________________________________________________________________________________
3. Yeasts are eukaryotic organisms – what does this mean?
__________________________________________________________________________________
4. Distinguish between aseptic and sterile techniques in microbiology
__________________________________________________________________________________
__________________________________________________________________________________
5. Describe how you collected the leaf sample
__________________________________________________________________________________
__________________________________________________________________________________
6. What part of the leaf provided the spores? ____________________________________________
7. How did you ensure that the samples were all of similar size?
__________________________________________________________________________________
8. Agar on its own has no nutrient value. What nutrient was in the agar that you used?
__________________________________________________________________________________
9. Describe how you transferred the yeast to the nutrient medium.
__________________________________________________________________________________
__________________________________________________________________________________
10. Give three precautions you took to prevent contamination of the dishes while setting up the
leaves in the dishes.
(a) _______________________________________________________________________________
(b) _______________________________________________________________________________
(c) _______________________________________________________________________________
11. What control was used?
_________________________________________________________________________________
117
12.
i. How did you attach the leaves to the lid of the dish?
__________________________________________________________________________________
ii. What surface of the leaf faced the nutrient agar? _______________________________________
Why?
_______________________________________________________________________________
iii. Describe what you did after attaching the leaves to the lid.
__________________________________________________________________________________
__________________________________________________________________________________
iv. After incubation what did you observe in the control dish?
_______________________________________________________________________________
v. Give two words to describe the yeast you observed. _____________________________________
13.Yeasts are sensitive to air pollution. If sample A came from a clean air environment and sample B
came from a busy town. Which sample would you expect to yield few colonies and why?
Sample____________________________________________________________________________
Why?
__________________________________________________________________________________
14. How would you safely dispose of the used petri dishes from the above experiment?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
15.The petri dishes that you used are not opened to view the colonies. Why?
__________________________________________________________________________________
__________________________________________________________________________________
118
Prepare and examine microscopically the transverse section of a
dicotyledonous stem (x100, x400)
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
119
Safety/Risks:
Labelled diagram:
Results:
X 100
X 400
Conclusion:
120
Skills for Preparing a TS of a Dicot Stem
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
Follow your step by step method
Listen to the teacher’s instructions
Use the blade to cut the section
Transfer sections using the paintbrush
Use the dropper
Manipulate the cover slip
Use the microscope
Observe the appearance of the sections under
different magnifications
Observe any differences between the sections
Write up the procedure
Draw and label a tissue plan
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of what
you learned in this activity such as making TS of LS
of other parts of a plant
Exercise caution for your personal safety and for
the safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hint for Making a TS of a Dicot Stem
• A simple microtome may be made from a nut and bolt. Almost remove the bolt from the
nut and fill the hole with hot wax. Place the sample in the wax and allow to cool. Then
screw the bolt into the nut, raising the wax and allowing a thin section to be cut.
• Fresh green stems, with no secondary thickening, are easiest to cut.
• Keep the stems wet, as turgid material is easier to cut thinly. Cutting under water can
also help with difficult specimens.
• All cuts should be made at an internode.
• A seeker may be used instead of a paintbrush to transfer the sections from the petri dish to
the microscope slide
121
Questions on Dicot Stem:
1. Define the term cotyledon.
__________________________________________________________________________________
__________________________________________________________________________________
2. Name a dicotyledonous plant _______________________________________________________
3. When using the light microscope, which objective lens will you first?
__________________________________________________________________________________
4. Why will you use a thin slice of stem?
__________________________________________________________________________________
__________________________________________________________________________________
5. Explain how you cut a thin section of stem
__________________________________________________________________________________
__________________________________________________________________________________
6. Name three tissue types in plants, giving the functions of each.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
7. If preparing a slide of a transverse section of a dicotyledonous stem, state the reason why you
used an herbaceous stem rather than a woody one.
__________________________________________________________________________________
__________________________________________________________________________________
8. Why was the stem cut between the nodes?
__________________________________________________________________________________
__________________________________________________________________________________
9. Name two of the tissues that are not vascular tissues.
__________________________________________________________________________________
10. Describe how you examined your section of stem with the microscope
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
122
Dissect, Display and Identify a Sheep’s Heart
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
123
Safety/Risks:
Labelled diagram:
Results:
Chamber
Size
Wall
small/large
thin/thick
Valve type
flaps
Left atrium
Bicuspid
Right atrium
Tricuspid
Left ventricle
Semi-lunar
Right ventricle
Conclusion:
124
Number of
Skills for Dissecting a Sheep’s Heart
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
Follow step by step method
Listen to the teacher’s instructions
Use the forceps, scissors and the scalpel
Explore using the seeker
Flag label the parts of the heart
Appreciate the significance of washing the heart
Observe the thickness of the left and right sides of
the heart and the left and right ventricles
Locate the ventral side of the heart
Identify the coronary groove and the 4 chambers
Observe the position of the main blood vessels
Compare the different chamber sizes
Identify the septum and the bicuspid valve
Locate the chordae tendinae & papillary muscles
Observe the tricuspid valve
Note the positions of the blood vessels
Identify the semi-lunar valve and the openings of
the coronary arteries
Locate the chordae tendinae and papillary muscles
Observe the tricuspid valve
Note the positions of the blood vessels going to
and coming from the heart
Identify the semi-lunar valve
Locate the openings of the coronary arteries
Examine the parts of the heart
Write up the procedure
Draw a labelled diagram
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of what
you learned in this activity for example dissection
of another organ
Exercise caution for your personal safety and for
the safety of others
Work as part of a group or team
Work in an organised and efficient manner
Clean up after the practical activity
Hints for dissecting the heart:
•
To locate the blood vessels before cutting:
(a)
Insert a rubber tube, attached to a tap, into part of the vena cava and gently
turn on the tap. The water comes out through the pulmonary artery.
(b)
Repeat this for the pulmonary vein. The water flows out of the aorta.
•
To show the pathway of blood through a coronary artery, you can inject a dye using a
plastic dropper.
•
To make flag labels use long pins and paper. Write with a pencil, as ink tends to run.
125
Questions on Heart Dissection:
1. How did you distinguish between the ventral (front) and dorsal (back) surfaces of the heart?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
2. How would you distinguish the left side from the right side of the heart?
__________________________________________________________________________________
__________________________________________________________________________________
3. Name the arteries through which the heart obtains its own blood supply. Are these arteries
visible in the dissected heart?
__________________________________________________________________________________
4. The heart contains cardiac muscle. Explain the meaning of the underlined term.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
5. What conclusions did you draw from the results obtained?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
6. What is the purpose of the semi lunar valve in the heart?
__________________________________________________________________________________
__________________________________________________________________________________
7. What separates the right side of the heart from the left?
__________________________________________________________________________________
8. Which chamber of the heart has the greatest amount of muscle in its wall?
__________________________________________________________________________________
126
9. Why is the wall of the left ventricle considerably thicker than that of the right?
__________________________________________________________________________________
__________________________________________________________________________________
10. What small openings can be found at the base of the aorta just above the semi-lunar valve?
__________________________________________________________________________________
__________________________________________________________________________________
11. Give reasons for the sterilisation of the dissecting equipment after dissection.
__________________________________________________________________________________
__________________________________________________________________________________
12. State the procedure that you followed to expose the semi lunar valve
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
13. Where in your dissection did you find the origin of the coronary artery?
__________________________________________________________________________________
14. State one way in which heart muscle differs from other muscles in the body.
__________________________________________________________________________________
_
127
Investigate the effect of exercise on the human pulse rate
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
128
Safety/Risks:
Labelled diagram:
Results:
Before
Trial 1
Trial 2
Trial 3
Total
Standing
Gentle
Brisk walking
Running
exercise
Resting
pulse rate
(beats/min)
Activity
walking
Pulse rate
(beats/min)
129
Average
Pulse Rate (bpm)
Sit
Gentle Walk
Brisk Walk
Conclusion:
130
Run
Questions on Pulse Rate investigation:
1. Name two sites on the human body where the pulse can be easily located.
(i)________________________________________________________________________________
(ii)________________________________________________________________________________
2. In which type of blood vessel (artery or vein) can the pulse be detected? Give a reason for your
answer.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
3. Why will you sit still for five minutes before commencing taking measurements?
__________________________________________________________________________________
__________________________________________________________________________________
4. Suggest a reason why you will measure your resting pulse rate three times.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
5. What do you expect to happen to your pulse rate as you increase the level of activity?
__________________________________________________________________________________
__________________________________________________________________________________
6. Give a reason for your answer.
__________________________________________________________________________________
__________________________________________________________________________________
7. Why is it important that you take readings immediately after each stage of the investigation?
__________________________________________________________________________________
__________________________________________________________________________________
131
8.
What factor will you keep constant during this investigation?
__________________________________________________________________________________
9. What factor will you vary during this investigation?
__________________________________________________________________________________
10. If it takes someone a long time to return to their resting pulse rate after exercise, what does this
indicate about their level of fitness?
__________________________________________________________________________________
__________________________________________________________________________________
11. The average rate of breathing of an adult at rest is: ______________________________. The
average pulse rate of an adult human at rest is: _______________________________
12. Complete the following by drawing a line through the incorrect term.
When you exercise, your breathing rate is faster / slower and is deeper / shallower. The lungs /
brain control breathing. When you exercise, you make more oxygen / carbon dioxide. The
amount of this gas builds up in the blood and the lungs / brain detect(s) the rise.
13. What is a pulse?
__________________________________________________________________________________
__________________________________________________________________________________
132
Investigate the effect of exercise on the breathing rate
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
133
Safety/Risks:
Labelled diagram:
Results:
Before
Trial 1
Trial 2
Trial 3
Total
Standing
Gentle
Brisk walking
Running
exercise
Resting
Breathing
Rate per min
Activity
walking
Breathing
rate
(breaths/min)
134
Average
Breathing Rate (breaths/min)
Sit
Gentle Walk
Brisk Walk
Conclusion:
135
Run
Questions on Effect of Exercise and the Breathing Rate:
1. Why will you sit still for five minutes before commencing taking measurements?
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
2. Why will you measure your resting breathing rate three times?
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
3. What do you expect to happen to your breathing rate as you as you increase the level of
activity?
_________________________________________________________________________________
_________________________________________________________________________________
4. Give a reason for your answer.
_________________________________________________________________________________
_________________________________________________________________________________
5. Why is important that you take readings immediately after each stage of the investigation?
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
6. If it takes someone a long time to return to their resting breathing rate after exercise, what does
this indicate about their level of fitness?
_________________________________________________________________________________
_________________________________________________________________________________
7. The average rate of breathing of an adult at rest is: _____________________________________
136
8. Name two sets of muscles used during inhalation.
_________________________________________________________________________________
_________________________________________________________________________________
9. Complete the following by drawing a line through the incorrect term.
When you exercise, your breathing rate is faster / slower and is deeper / shallower. The lungs / brain
control breathing. When you exercise, you make more oxygen / carbon dioxide. The amount of this
gas builds up in the blood and the lungs / brain detect(s) the rise.
137
Skills for measuring effect of exercise on Pulse and Breathing Rates
Skill
1. Following
Instructions
2. Manipulation of
apparatus
3. Observation
4. Recording
5. Interpretation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Use the timer
Use the pulse rate meter or data logger if using
Find a pulse or observe the breathing rate
Observe the effect of exercise on the pulse
and breathing rate
Write up the procedure
Record the pulse and breathing rate before
and after various rates of exercise
Tabulate results
Draw a bar chart
Draw reasonable conclusions from your
observations and results
6. Application
7. Organisation
Become aware of any other application(s) of
what you learned in this activity for example
the effect of exercise on your body
temperature
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Work in an organised and efficient manner
Hints for measuring the effects of Exercise on Pulse and Breathing Rates
•
It is not essential to undergo each level of exercise for this activity e.g. you may stop at
brisk walking.
•
The pulse can be felt at various points on the body where the arteries are just under the
skin, such as the neck, and wrist.
•
The thumb should not be used when measuring the pulse. The thumb has its own pulse
and may confuse your count.
•
•
Do not press too hard when feeling for the pulse or you may block it.
Heart recovery time can also be determined while doing this activity. After running, the
pulse is measured and recorded every minute until it returns to resting heart rate. The time
taken to return to resting heart rate is known as the heart recovery time.
•
To measure breathing rate: breathing in and out once is counted as one breath, so just count
the out breaths. Do keep in mind that it is difficult to accurately measure the effect of
exercise on breathing as there is a certain degree of voluntary control involved.
138
Investigate the effect of IAA growth regulator on plant tissue
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
139
Safety/Risks:
Labelled diagram:
140
Results:
Concentration
Length of roots (mm)
Total
Average
Percentage
of IAA
Seed
Seed
Seed
Seed
Seed
Length
Length
stimulation
(ppm)
1
2
3
4
5
(mm)
(mm)
or inhibition
0 (control)
10-4
10-3
10-2
10-1
1
101
102
141
Concentration
Length of shoots (mm)
Total
Average
Percentage
of IAA
Seed
Seed
Seed
Seed
Seed
Length
Length
stimulation
(ppm)
1
2
3
4
5
(mm)
(mm)
or inhibition
0 (control)
10-4
10-3
10-2
10-1
1
101
102
Result:
Conclusion:
142
Plot a graph of percentage stimulation and inhibition of root and shoot growth against IAA
concentration.
Put IAA concentration on the X axis and Average length or Percentage stimulation or inhibition on
the Y axis
143
Skills for Investigating the Effect of IAA
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Use the syringes and the droppers
Carry out a serial dilution
Place the seeds on the acetate grids in the
dishes
Reduce the trapped air around the seeds
Spread the cotton wool to absorb the
excess solution
Put the bases of the dishes in place
Secure the dishes with adhesive tape
Stand the dishes vertically
Use the thermometer
Observe the growths of the roots and the
shoots
Note the difference in lengths of the roots
and the shoots in the different solutions
Write up the procedure
Record the length of the roots and the shoots
Calculate the average length of the roots and
the shoots
Calculate the percentage average
stimulation or inhibition of the roots or the
shoots by each solution
Tabulate the results
Draw a graph with labelled axes
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity such as the
effect of rooting powders on cuttings
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Investigating the Effects of IAA
•
All the dishes containing the same concentration of IAA from the class may be supported in
separate one-litre plastic bottles as shown.
•
Make acetate grids by photocopying graph paper onto two acetate sheets.
144
Questions on IAA:
1. Name the plant that you used in this experiment _______________________________________
2. What is IAA?
_______________________________________________________________________________
3. What biomolecule would you equate IAA to in an animal? ________________________________
4. Name the plant you used in this experiment. __________________________________________
5. State the location in a flowering plant where a growth regulator is secreted.
__________________________________________________________________________________
6. Why is a control necessary?
__________________________________________________________________________________
__________________________________________________________________________________
7. Why are the acetate grids placed in each petri dish?
__________________________________________________________________________________
__________________________________________________________________________________
8. How would you make up serial dilutions of IAA?
__________________________________________________________________________________
__________________________________________________________________________________
9. How did you ensure that there was sufficient water for the seeds during the experiment?
__________________________________________________________________________________
__________________________________________________________________________________
10.What is a coleoptile?
__________________________________________________________________________________
145
11.Give an example of growth regulators that promotes and inhibit growth
__________________________________________________________________________________
__________________________________________________________________________________
12.The graph below shows the growth response of a stem and a root to varying concentrations of
auxin.
(a) At what concentration of auxin is there maximum root growth? ___________________________
(b) At what concentration of auxin is there maximum stem growth? __________________________
(c) What effect does 10-2 ppm have on root growth? _______________________________________
13. Name A in the diagram below _____________________________________________________
What is the purpose of A in this experiment? _______________________________________
How would you make up solutions of different concentrations from a stock solution of IAA?
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
146
Investigate the effects of water, oxygen and temperature on
germination
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
147
Safety/Risks:
Labelled diagram:
Results:
Dish
Germination
A – with oxygen and suitable temperature (no water)
B – with water and oxygen (unsuitable temperature)
C – with water and suitable temperature (no oxygen)
D – with water, oxygen, and a suitable temperature
Conclusion:
148
Skills for Germination
Skill
1. Following Instructions
2. Manipulation of
apparatus
3.
Observation
4. Recording
5. Interpretation
6. Application
7. Organisation
Achieved
Familiarise yourself with all procedures
before starting
Follow step by step method
Listen to the teacher’s instructions
Fill and empty the pipette
Set up the water bath
Use the test-tube holder safely
Use the timer
Label the tubes correctly
Swirl the tubes
Observe the appearance of the seeds at the
start of the activity
Check the seeds for germination
Observe the effect of suitable/unsuitable
conditions
Write up the procedure
Record the development of the seeds
Draw reasonable conclusions from your
observations and results
Become aware of any other application(s) of
what you learned in this activity for example
the effects of external conditions on plant
reproduction
Exercise caution for your personal safety and
for the safety of others
Work as part of a group or team
Label as appropriate
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Germination:
•
•
•
•
•
Radish seeds are recommended, as they usually germinate after 24 hours in ideal conditions.
Some seeds are not easily available all year round. March/April is a good time to buy them.
The cotton wool only needs to be moistened, not saturated.
Ensure that the cotton wool is absorbent.
If access to an incubator is a problem, heating mats, which are available from plant
nurseries, can be used. In the event that neither is available, room temperature will
suffice.
149
Questions on Germination:
1. Explain what is meant by seed germination.
__________________________________________________________________________________
__________________________________________________________________________________
2. Why is digestion necessary in a germinating seed?
__________________________________________________________________________________
__________________________________________________________________________________
3. Digestive activity during germination can be demonstrated by using agar plates.
What is an agar plate?
__________________________________________________________________________________
__________________________________________________________________________________
4. An extra food material is added to the agar plate for this demonstration.
Give an example of such an extra food material. _______________________________________
5.
What control did you use for this experiment?
__________________________________________________________________________________
__________________________________________________________________________________
8. Describe the results that you obtained in:
1.
The experimental plate.
__________________________________________________________________________________
2.
The control plate.
__________________________________________________________________________________
9.
Why should you cross-reference your results with other groups in the class?
__________________________________________________________________________________
__________________________________________________________________________________
10. Name another factor apart from temperature that might be different in a fridge, compared to
the other three dishes.
__________________________________________________________________________________
__________________________________________________________________________________
150
11. How many seeds are used in each petri dish for this investigation? Give a reason for the number
used
__________________________________________________________________________________
__________________________________________________________________________________
12.
What result would you expect to observe after a few days?
__________________________________________________________________________________
__________________________________________________________________________________
13.
Explain the need for water, oxygen and temperature during germination
Water:
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
Temperature:_______________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
Oxygen:___________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
14. Is it the air temperature or soil temperature that controls germination?
__________________________________________________________________________________
__________________________________________________________________________________
15. Give one location in a seed in which food is stored. ____________________________________
16. Name a carbohydrate that you would expect to be present in this food store
______________________________________________________________________________
______________________________________________________________________________
17. Explain the term embryo.
_______________________________________________________________________________
_______________________________________________________________________________
18. Seeds may remain inactive for a period before germination. What term is used to describe this
period of inactivity? _______________________________________________________
151
Use starch agar or skimmed milk plates to show digestive activity
during germination
Date the experiment was completed: _________________
Materials/Equipment/Apparatus:
Procedure/Method:
List steps taken with reasons:
Safety/Risks:
152
Labelled diagram:
Results:
Starch Agar Plates
Colour Under Seeds
Unboiled: Test with iodine
Boiled: Test with iodine
Unboiled: Test with Biuret
Boiled: Test with Biuret
Give Description
Skimmed Milk Powder Plates
Colour Under Seeds
Give Description
Conclusion:
153
Skills for digestive activity in seeds
Skill
8. Following
Instructions
9. Manipulation
of apparatus
10. Observation
11. Recording
12. Interpretation
13. Application
14. Organisation
Achieved
Familiarise yourself with all procedures before
starting
Follow step by step method
Listen to the teacher’s instructions
Use the thermometer
Label the plates
Boil the seeds
Use the timer
Split the seeds
Sterilise the forceps and the seeds
Transfer the seeds onto the agar
Flood the plates with iodine solution/biuret
reagent
Pour off the excess iodine solution/biuret reagent
Observe the difference between the control and
experiment plates Observe the change in the
starch/skimmed milk agar
Observe the effect of iodine solution/biuret
reagent Recognise the benefit of holding the
plate up to the light
Write up the procedure
Draw a labelled diagram for apparatus
Draw reasonable conclusions from your
observations and results
Appreciate the importance of leaving the plates
for the appropriate time
Become aware of any other application(s) of
what you learned in this activity
Exercise caution for your personal safety and for
the safety of others
Work as part of a group or team
Use aseptic technique throughout
Work in an organised and efficient manner
Clean up after the practical activity
Hints for Digestion of Seeds
•
•
•
•
•
•
Pre-soak seeds for two days
Take care in moving the agar plates with the seeds, to prevent the seeds from sliding.
Label the tops and bases of the plates and keep the labelling small.
A blunt forceps is preferable to a sharp one as it is less likely to damage the seeds.
A forceps can be used to hold the seed in place while splitting it with the backed blade.
Have labelled petri dishes (‘Raw’ and ‘Boiled’) to hand when splitting the seeds.
154
Questions on digestive activity in seeds:
1.
What type of agar plates did you use? ____________________________________________
2.
How were the seeds placed on the petri dish?
___________________________________________________________________________
3.
What aseptic technique did you use?
___________________________________________________________________________
___________________________________________________________________________
4. What reagent was used to investigate digestive activity? __________________________________
5. How did you dispose of the dishes once the experiment was finished? ______________________
__________________________________________________________________________________
6. In what form is carbohydrate stored in:
(i) humans: ___________________________ (ii) a broad bean: ______________________________
7. State where carbohydrates are stored in:
(i) humans: _________________________ (ii) a broad bean: _______________________________
8. Broad bean is a dicotyledonous, non-endospermic seed. Explain the underlined terms.
__________________________________________________________________________________
__________________________________________________________________________________
9. Maize is a monocotyledonous, endospermic seed. Explain the underlined terms.
_________________________________________________________________________________
10. During the digestive activity of the seed you used, state:
(i) Enzyme: ______________________________________________________________
(ii) Substrate: ____________________________________________________________
(iii) Product(s): ____________________________________________________________
155
Visuals for Experiments
Conduct a quantitative test for fat:
156
Visuals for Experiments
Conduct a quantitative test for protein:
157
Conduct a quantitative test for starch:
158
Conduct a quantitative test for reducing sugar:
159
Ecology - Some Animal Collection Equipment
Pooter
Pitfall Trap
Insect Net
Mammal Trap
Beating Tray
Tullgren Funnel
160
Ecology - Some Abiotic Measurement Equipment
Hygrometer
Quadrats
Anemometer
Frame Quadrat
Soil
ther
mom
eter
Air Thermometer
25 Point Grided Quadrat
161
Be familiar with and use the light microscope:
162
163
Prepare and examine one animal cell using the light microscope:
164
165
Prepare and examine one plant cell using the light microscope:
166
167
Investigate the effect of pH on the rate of amylase activity:
168
169
Investigate the effect of pH on the rate of catalase activity:
170
171
Investigate the effect of temperature on the rate of catalase activity:
172
173
Investigate the effect of temperature on the rate of amylase activity:
174
175
Investigate the effect of heat denaturation on the activity of catalase:
176
177
Investigate the effect of heat denaturation on the activity of amylase:
178
179
Prepare one enzyme immobilisation and examine its application:
180
181
182
Investigate the influence of carbon dioxide concentration on the rate of photosynthesis:
183
184
Investigate the influence of light intensity or carbon dioxide on the rate of photosynthesis:
185
Prepare and show the production of alcohol by yeast:
186
187
Conduct any activity to demonstrate osmosis:
188
Isolate DNA from plant tissue:
189
190
Investigate the growth of leaf yeast using agar plates and controls:
191
Prepare and examine microscopically the transverse section of a dicotyledonous stem:
192
Investigate the effect of exercise on heart rate:
193
194
Investigate the effect of exercise on breathing rate:
195
196
Dissect, display and identify an ox’s or a sheep’s heart:
197
198
199
Investigate the effect of IAA Growth regulator on plant tissue:
200
201
Investigate the effect of water, oxygen and temperature on germination12:
202
Use starch agar or skimmed milk plates to show digestive activity during germination:
203
204