The 7 Required Labs
1. Magnification and Cellular Structure – Topic 1.1
2. Estimation of Osmolarity in Tissues – Topic 1.4
3. Factors Effecting Enzyme Activity – Topic 2.5
4. Separation of Photosynthetic Pigments – Topic 2.9
5. Mesocosms and Sustainability – Topic 4.1
6. Monitoring Ventilation in Humans – Topic 6.4
7. Transpiration Rates Using Potometers (HL) – Topic 9.1
1. Magnification and Cellular
Structure
Objectives
a) To use a light microscope and investigate the
structure of cells and tissues, including drawing of
cells and cellular structures.
b) Calculate the magnification of drawings and the
actual size of structures and ultrastructures shown
in drawings or micrographs.
Illustration
showing how to
prepare a wet
mount.
Remember to keep your units
consistent.
Can you use the scale bar for
calculations?
1. Magnification and Cellular Structure
Practice Makes Perfect…
 http://www.thinkib.net/biology/page/17083/calculat
ing-magnification-and-size
1. Magnification and Cellular Structure
Helpful Tutorials
Calculating I, A and M
 http://www.youtube.com/watch?v=wPYBLysk12M
 http://www.youtube.com/watch?v=NFVSWOaU0f0
&feature=related
1. Magnification and Cellular Structure
2. Estimation of Osmolarity
in Tissues
Objectives
a) Compare hypertonic, hypotonic and isotonic
solutions.
b) Predict what will occur when plant cells are placed in
various solutions.
Comparison of Plant and Animal
Cells in Solution
2. Estimation of Osmolarity in Tissues
Lab Tutorial
Refresh Your Memory
 https://www.youtube.com/watch?v=LeS2-6zHn6M
2. Estimation of Osmolarity in Tissues
Osmolarity Virtual Lab
http://indstudy1.org/hs/999102059004/Lesson5/Lab5.s
wf
Complete the Virtual Lab and ask yourself these questions…
1. What are the variables in this experiment (control,
independent and dependent)?
2. Explain how this relates to medicine and why cell samples
need to be bathed in the same osmotic solution as their
contents?
2. Estimation of Osmolarity in Tissues
3. Factors Effecting Enzyme
Activity
Objectives
1.
Determine how different substrate concentrations affect a
protease’s activity (measured as the reaction rate).
2.
Define the term, ‘denature’.
3.
Predict what will occur to the rate of an enzymatic reaction
as the substrate concentration increases.
Understand the Graphs
You should be able to:
1. Draw each of the
graphs on the left.
1. Label the X and Y axis
of each.
1. Explain, in scientific
terms, what is taking
place and why.
1. Title each of the
graphs.
3. Factors Effecting Enzyme Activity
The Experiment
 You are going to use a commercially available
protease, extracted from bacteria. It will hydrolyze
most proteins to amino acids.
 As substrate we will use a solution of skimmed milk
powder, which contains the colloidal milk protein
casein. This causes the cloudy white appearance of
the milk powder, by scattering light.
 The colorimeter (set on ‘Abs’) will be used to measure
the amount of substrate (casein) remaining.
3. Factors Effecting Enzyme Activity
Points to Consider…
 State the RQ for this investigation.
 Explain how the colorimeter works and predict the
results if using varying concentrations of casein.
 Deduce how the results may relate to the graph below.
3. Factors Effecting Enzyme Activity
Virtual Lab
http://www.phschool.com/science/biolog
y_place/labbench/lab2/intro.html
 Check out this virtual lab. It will help you revise the
key concepts associated with Enzyme Catalysis.
3. Factors Effecting Enzyme Activity
4. Separation of Photosynthetic
Pigments
Objectives
 State that chlorophyll is the main photosynthetic
pigment.
 Outline the differences in absorption of red, blue and
green light by chlorophyll.
 Calculate the Rf values for various photosynthetic
pigments.
An Overview
 Photosynthesis depends on the
absorption of light energy by
pigments. These include the
chlorophylls and various
accessory pigments, which
absorb other wavelengths and
thus contribute to the overall
efficiency of photosynthesis.
4. Separation of Photosynthetic Pigments
The Basic Principle
 This migration of pigment relative to migration of
solvent is expressed as a constant, Rf (Reference
front).
It can be calculated by using the formula:
Virtual Lab from Pearson
http://www.phschool.com/science/biolog
y_place/labbench/lab4/intro.html
4. Separation of Photosynthetic Pigments
A Few Thoughts…
 Discuss the many types of chromatography and state
which type we used in this investigation and why.
 Draw, label and annotate a general diagram of the
apparatus used in this experiment.
 Explain how Rf values can be validated and how
scientists can compare their results to known values.
Why is this helpful?
4. Separation of Photosynthetic Pigments
5. Mesocosms and Sustainability
Objectives
 To understand that mesocosms are models of larger
ecosystems.
 Define the concept of a ‘closed ecosystem’, one in
which energy enters and leaves but matter does not.
Ecosystems
 Compare ‘open’ and ‘closed’ ecosystems. Is any ecosystem
really every ‘closed’?
 Design and build a mesocosm.
 Discuss how carbon and water cycle through your mecososm.
5. Mesocosms and Sustainability
Check out this guy’s
ecosystem!
 David Latimer
planted his bottle
garden in 1960 and
hasn’t watered it since
1972
Read about it here…
http://www.dailymail.co.uk/sciencetech/ar
icle-2267504/The-sealed-bottle-gardenthriving-40-years-fresh-air-water.html
5. Mesocosms and Sustainability
6. Monitoring Ventilation in
Humans
Objective
 To understand that the lungs are actively ventilated to
ensure that gas exchange can occur passively.
You should be able to design and
carry out a simple breathing
experiment than analyze your results
and draw conclusions?
6. Monitoring Ventilation in Humans
Review the Mechanisms
of Breathing
https://www.youtube.com/watch?v=GD-HPx_ZG8I
6. Monitoring Ventilation in Humans
Spirometry Test for Lung
Function
a) Simple animation showing
how Spirometry works
b) Extend Yourself
https://www.youtube.com/watch?v=hQzN
G89pESQ
https://www.youtube.com/watch?v=QJcAJ
HFqXZg
6. Monitoring Ventilation in Humans
7. Transpiration Rates Using
Potometers (HL)
Objectives
 Describe the process of
transpiration in vascular
plants.
 Investigate the effect of
various environmental
factors on the transpiration
rate in plants.
Transpiration Review
https://www.youtube.com/watch?v=U4rzL
hz4HHk
Complete the Virtual Lab
https://www.classzone.com/books/hs/ca/sc
/bio_07/virtual_labs/virtualLabs.html
7. Transpiration Rate Using Potometers
Discuss environmental factors that
affect transpiration rate…
http://users.rcn.com/jkimball.ma.ultranet/B
iologyPages/T/Transpiration.html
7. Transpiration Rate Using Potometers
Additional Resource
 http://www.thinkib.net/biology/page/16860/lab-
protocols-for-new-ib-guide
The site above has briefs for all of
the IB biology labs.