IB Biology Y2
Semester Final
Exam Review
Name: __________________________________ Class: ________________
Exam Date: ______________________ December ______, 2013 at ______________ am.
Exam Format:
o Topics covered:
o CORE: 1, 2, 3, 4 (4.1), 5, 6 (6.1-6.4)
o HL: 7, 8, 9, 11 (11.1,11.3)
o Options: G
o Exam Length: 2 hours
o Questioning: Multiple choice, Short Answer, Long Answer, Graph Analysis, Calculations,
Diagram drawing, labeling and identification.
o Materials needed for Exam: pen, ruler and calculator (TI-83 – need for stats)
o Exam Protocols (Rules):
o Students should write their exams in blue or black ink and not use any whiteout
for corrections.
o Use washroom before entering exam room. You will not be allowed to leave in the
first 30 minutes of exam.
o No backpacks, phones, iPods, or computers allowed in exam room. All personal
belongings need to be locked in your lockers.
o You may not communicate in any way with any person in the exam room except
the supervisor. At the end of the exam, you should remain in your seats until all
of the exam papers have been collected and you have been given permission to
leave.
o Do not open your examination booklet until you are instructed to do so.
o A breach of exam rules could result in your paper being cancelled.
o Ex. If a student does have a phone or cheat notes with them during the exam, their
exam will no longer be valid.
Before you complete the sample questions in this review pack, you should have studied your
biology syllabus statements! Use these sample questions as a practice exam.
Topic 1
1. The table below shows the level of hemoglobin measured in two different groups of athletes.
Hemoglobin /
3
grams per 100 cm
Number of
athletes tested
Standard deviation /
3
grams per 100 cm
Group A
12.6
200
0.8
Group B
11.9
220
3.2
Which of the following statements is correct?
A.
Results from group B are more accurate because more athletes were tested.
B.
Results from group B are more reliable because it has a higher standard deviation.
C.
More athletes have their hemoglobin concentration close to the mean in group A than in group B.
D.
These results indicate that the level of hemoglobin follows a normal distribution.
(Total 1 mark)
2.
Which hypothesis can be tested using the t-test?
A.
The difference in variation between two samples is not significant.
B.
The difference between observed values and expected values is not significant.
C.
The change in one variable is not correlated with a change in another variable.
D.
The difference between the means in two samples is not significant.
(Total 1 mark)
3.
The lengths of a sample of tiger canines were measured. 68% of the lengths fell within a range between 15 mm and
45 mm. The mean was 30 mm. What is the standard deviation of this sample?
A.
5 mm
B.
15 mm
C.
7.5 mm
D.
30 mm
(Total 1 mark)
4. What does the following scatter graph show?
A.
B.
C.
D.
No correlation between these variables
Strong positive correlation between these variables
Strong negative correlation between these variables
Weak negative correlation between these variables
(Total 1 mark)
5. What does the size of the standard deviation indicate about data?
A.
How accurately the data were measured
B.
How widely the data are spread above and below the mean
C.
Whether the mean is larger or smaller than it should be
D.
Whether the reliability of the data is greater or less than 68%
(Total 1 mark)
Ans: C,D,B,B,B
Topic 2:
1. Which of the following will contribute to the cell theory?
I.
Living organisms are composed of cells.
II.
All cells come from pre-existing cells by mitosis.
III. Cells are the smallest units of life.
A.
I only
B.
II only
C.
I and III only
D.
I, II and III
(Total 1 mark)
2.
A red blood cell is 8 μm in diameter. If drawn 100 times larger than its actual size, what
diameter will the drawing be in mm?
A.
0.08 mm
B.
0.8 mm
C.
8 mm
D.
80 mm
(Total 1 mark)
3.
A cell has cytoplasm, a cell wall, naked DNA and ribosomes. Based on this information, what
type of cell could this be?
A.
A cell from a pine tree
B.
A grasshopper cell
C.
A human red blood cell
D.
A bacterium
4.
What do diffusion and osmosis have in common?
A.
They only happen in living cells.
B.
They require transport proteins in the membrane.
C.
They are passive transport mechanisms.
D.
Net movement of substances is against the concentration gradient.
5.
The diagram below shows a cell during mitosis.
(Total 1 mark)
(Total 1 mark)
What are the structures and stage of mitosis?
A.
B.
C.
D.
Stage of mitosis
metaphase
anaphase
anaphase
metaphase
Structure I
chromatid
centromere
chromatid
centromere
Structure II
nuclear membrane
plasma membrane
nuclear membrane
plasma membrane
(Total 1 mark)
ANS: C,B,D,C,D
6. The electron micrograph below shows the ultrastructure of part of an animal cell.
[Source: Reproduced with the kind permission of the Electron Microscopy Facility, Trinity College, Hartford,
Connecticut, USA, and Professor Daniel G. Blackburn.]
(a)
Identify the structure labelled I.
......................................................................................................................................
(1)
(b) Explain briefly how materials produced in the structure labelled I are transported to the
plasma membrane.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(c)
Outline the function of the mitochondria in the cell.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(d)
Suggest why the two labelled mitochondria are different shapes in the micrograph.
......................................................................................................................................
(1)
(Total 6 marks)
7. (a)
Outline the bonding between DNA nucleotides.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(b)
Explain how chemical bonding between water molecules makes water a valuable coolant in
living organisms.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(c)
Describe the movement of water across membranes.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(d)
State the role of water in photosynthesis.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 8 marks)
8. The following sequence of pictures, made using an electronic imaging technique, shows a cell
undergoing division.
[Adapted by permission from Macmillan Publishers Ltd, Fuller, B G et al. 2008. “Midzone activation of aurora B
in anaphase produces an intracellular phosphorylation gradient”. Nature. Vol 453.]
(a)
State the stage of mitosis typified by image II.
......................................................................................................................................
(1)
(b)
List two processes that involve mitosis.
......................................................................................................................................
......................................................................................................................................
(2)
(c)
State the process that results in tumour (cancer) formation or development.
......................................................................................................................................
(1)
(d) Explain, using one example, how non-disjunction in meiosis can lead to changes in
chromosome number.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 6 marks)
ANS:
6.(a)
rough endoplasmic reticulum/RER/rough ER / ribosome
(b)
(c)
(d)
1
vesicles are formed (from the rough ER);
they are received by Golgi apparatus;
Golgi apparatus forms vesicles that transport substances to membrane;
2 max
aerobic respiration takes place in the mitochondria;
important for energy/ATP production;
pyruvate broken down into carbon dioxide and water;
2 max
they are cut in different planes / due to three-dimensional nature/shape
1
[6]
7. (a) hydrogen bonds between nucleotides of opposite strands/complementary
bases/adenine and thymine and cytosine and guanine;
covalent bonds between nucleotides within strands/between
sugar/deoxyribose and phosphate;
(b)
(c)
(d)
2
hydrogen bonding between water molecules;
breaking (hydrogen bonds) needs/removes energy/heat;
hydrogen bonds must break when water evaporates/vaporizes;
2 max
osmosis / moves passively;
from regions of low solute/high water potential/concentration to
high solute concentration / low water potential/concentration;
passes through protein channels/aquaporins/selectively-permeable
membrane;
2 max
water molecules undergo photolysis/are split by light energy;
forms oxygen as a by-product;
hydrogen helps power the fixation of carbon (into organic molecules);
2 max
[8]
8. (a)
anaphase
(b)
growth (through increasing cell number);
embryonic development;
tissue production/repair;
(asexual) reproduction;
(c)
uncontrolled mitosis/cell division
(d)
pair of homologous chromosomes moves in same direction/does not
separate during anaphase I / chromatids move in same direction/do
not separate during anaphase II;
leaving a cell with an (some) extra chromosome(s)/missing
chromosome(s);
an example; (e.g. Down syndrome / trisomy 21);
1
2 max
1
2 max
[6]
Topic 3:
1. Which of the following are connected by hydrogen bonds?
A.
Hydrogen to oxygen within a molecule of water
B.
Phosphate to sugar in a DNA molecule
C.
Base to sugar in a DNA molecule
D.
Hydrogen to oxygen between two different molecules of water
(Total 1 mark)
2.
The graph below shows the effect of substrate concentration on enzyme activity. What
conclusion can be drawn about section X of the graph?
A.
B.
C.
D.
The enzyme has started to denature and the reaction slows down.
The reaction has finished and the substrate has been used up.
The enzyme is saturated and is working at its maximum reaction rate.
Some of the enzyme has been consumed and the reaction has reached a plateau.
(Total 1 mark)
3.
Which type of molecule is shown in the diagram below?
A.
B.
C.
D.
Peptide
Carbohydrate
Lipid
Nucleic acid
(Total 1 mark)
4.
The percentage of thymine in the DNA of an organism is approximately 30%. What is the
percentage of guanine?
A.
70%
B.
30%
C.
40%
D.
20%
(Total 1 mark)
5.
What is denaturation?
A.
A structural change of a protein that results in the loss of its biological properties
B.
A change in the genetic code of an organism
C.
A change in the amino acid sequence of a protein causing a disruption of its 3D shape
D.
The process by which amino acids are broken down and ammonia is released
(Total 1 mark)
ANS: D, C, A, D, A
6. (a) Outline condensation and hydrolysis reactions using a different example for each.
(5)
(b)
Outline the effect of temperature and substrate concentration on the activity of
enzymes.
(4)
(c)
Explain methods by which the rate of photosynthesis can be measured, including
conditions that affect the rate.
(9)
7. Explain the link reaction that occurs between glycolysis and the Krebs cycle.
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
(Total 4 marks)
8. a) State two functions of proteins, giving a named example of each.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(b)
Explain the significance of polar and non-polar amino acids. (HL only)
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(Total 5 marks)
9. Explain the control of metabolic pathways.
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
(Total 3 marks)
10. (a)
Define active site.
......................................................................................................................................
......................................................................................................................................
(1)
(b)
Explain enzyme-substrate specificity.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(Total 4 marks)
11. (a)
State the location in the chloroplast of the following reactions of photosynthesis.
Light-independent reactions: .......................................................................................
Light-dependent reactions: ..........................................................................................
(2)
(b)
Explain what happens to the electrons in the light-dependent reactions of
photosynthesis. (HL only)
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(Total 5 marks)
ANS:
6. (a)
condensation reactions involve joining subunits/molecules/monomers;
with the release of water;
hydrolysis reactions involve splitting molecules into subunits/
molecules/monomers;
with the addition of water;
example of condensation reaction;
(e.g. amino acid + amino acid yields dipeptide + water)
example of hydrolysis reaction;
(e.g. disaccharide + water yields two monosaccharides)
Examples can be shown in words or chemical form.
(b)
(c)
enzymes most active at one temperature/optimum temperature;
any deviation from that temperature lowers the enzyme activity;
denaturing/change in active site/no activity at higher temperatures /
inactivated at (very) low temperatures;
increasing the substrate concentration increases the enzyme
activity/more enzyme–substrate complex formed/more
collisions between enzyme and substrate;
eventually no increase in enzyme activity with increased substrate
concentration / plateau when enzymes are working to the
maximum/when all active sites occupied/saturated;
Accept answers shown graphically.
measuring oxygen release;
measuring volume / counting rising oxygen bubbles / counting
rising disks;
measuring carbon dioxide intake/uptake;
CO2 can be measured by change in pH / increase in pH shows
an increase in CO2 fixation;
increase in biomass would be an indirect measure of
photosynthesis / measure of net photosynthesis;
measure starch production / dry organic mass;
increasing temperature would increase the rate of photosynthesis;
provided the temperature did not go above optimum temperature
of enzymes;
5 max
4 max
increasing carbon dioxide concentration would increase the rate
of photosynthesis;
higher light intensity would increase the rate of photosynthesis;
light of different wavelengths / blue and red light can affect
photosynthesis / green wavelength usually not absorbed;
example of a detailed experiment;
(e.g. drawing or explanation of waterweed under funnel and
tube collecting bubbles of oxygen)
9 max
(Plus up to [2] for quality)
[20]
7.
pyruvate (from glycolysis) enters a mitochondrion;
enzymes in the matrix remove one carbon dioxide and hydrogen from
the pyruvate;
hydrogen is accepted by NAD/forms NADH;
removal of hydrogen is oxidation;
removal of carbon dioxide is decarboxylation;
the whole process/link reaction is oxidative decarboxylation;
the product is an acetyl group which reacts with CoA/coenzyme A;
acetyl CoA enters Krebs cycle;
Accept any of the above points in the form of a clearly drawn and
correctly labelled diagram.
4 max
[4]
8.
(a)
(b)
enzymes/biological catalyst —amylase/protease/lipase/catalase;
defence/immunity — immunoglobin/antibody;
structure—collagen;
movement — actin/myosin;
transport—hemoglobin;
synthesis — ligase/DNA polymerase;
hormonal communication — insulin/luteinizing hormone; MUST be
proteinaceous
food stores — casein in milk;
pigments—opsin;
Accept any other valid responses.
2 max
polar amino acids have hydrophilic R groups, non-polar have hydrophobic
R groups;
non-polar amino acids in centre of water-soluble proteins stabilise their
structure;
non-polar amino acids cause proteins to remain embedded in membrane;
polar amino acids on surface of proteins make them water-soluble;
polar amino acids create hydrophilic channels/protein pores in membranes;
enzyme active site specificity depends on amino acids present/polar and
non-polar amino acids can play a role in substrate interactions at the
active site;
3 max
[5]
9.
metabolic pathway is a series of reactions carried out in a particular sequence;
products of one reaction become substrates for the next;
each reaction is enzyme-catalyzed (and thus represents point of control);
some enzymes are allosteric;
allosteric control / end-product inhibition/negative feedback;
end-product acts as inhibitor of enzyme at beginning of pathway;
product binding changes the conformation of the active site so substrate of the
pathway can no longer bind;
3 max
[3]
10. (a) site on surface/portion of the enzyme/protein to which the substrate binds
(b)
enzymes fit together with substrates similar to a lock and key;
active site has shape that gives specificity;
enzymes catalyze a reaction with a specific substrate;
example of named enzyme and its substrate;
substrate held precisely in (optimum) position to make/break bonds/carry
out reaction / chemical interaction occurs between enzyme and substrate;
Accept these points shown in an annotated drawing.
1
3 max
[4]
11. (a) light-independent reactions: stroma;
light-dependent reactions: thylakoid / grana;
(b)
absorb photons of light / photoactivation;
raised to a higher energetic level;
pass from molecule to molecule;
drop back to own level emitting energy;
2
3 max
Topic 4:
1. the following diagram, which pair represents homologous chromosomes?
A.
B.
C.
D.
1 and 2
3 and 4
2 and 5
4 and 6
(Total 1 mark)
5. Which of the following is the cause of sickle-cell anemia?
A.
Tryptophan is replaced by leucine.
B.
Leucine is replaced by valine.
C.
Glutamic acid is replaced by valine.
D.
Lysine is replaced by glutamic acid.
(Total 1 mark)
ANS: D,C
6. The karyotype below shows the chromosomes from a person with Down syndrome.
(a) State the evidence provided by the karyotype that shows this person has Down
syndrome.
......................................................................................................................................
(1)
(b)
Outline how Down syndrome occurs due to meiosis.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(c)
Determine, giving a reason, the sex of the person in the karyotype.
......................................................................................................................................
......................................................................................................................................
(1)
7. (a) Gene transfer to bacteria often involves small circles of DNA into which genes can be
inserted. State the name of a small circle of DNA, used for DNA transfer, in bacteria.
......................................................................................................................................
(1)
(b)
The diagram below shows a cut circle of DNA into which a gene is being inserted.
Before it can be transferred into a bacterium, the ring must be altered, using an enzyme.
Outline what must be done next to complete the process of gene insertion into the DNA
circle, including the name of the enzyme that is used.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
6. (a)
three copies/extra copy/trisomy of chromosome/pair 21
Do not accept chromatid.
(b)
occurs due to non-disjunction;
(homologous) chromosome/pairs/sister chromatids fail to separate;
some gametes have an extra chromosome;
(c)
male as sex chromosomes different size/both X and Y chromosomes present
To award [1], reason must be given.
(d)
gene for colour blindness is carried on X chromosome (sex linkage);
males have only one X chromosome so the allele is always expressed /
absent from Y chromosome;
the allele of the gene for colour blindness is recessive;
females must be homozygous to be colour-blind / heterozygous
females are carriers but not colour-blind;
1
2 max
1
2 max
[6]
7.
(a)
plasmid
(b)
DNA ligase involved; (DNA required to be consistent with syllabus)
seals gaps/nicks in DNA (strands);
makes sugar-phosphate bonds;
(c)
named example of DNA source and organism to which it is transferred;
benefit of the example of gene transfer;
possible harm from the example of gene transfer;\
1
2 max
Structured Data Analysis:
Rice (Oryza sativa) is usually intolerant to sustained submergence under water, although it grows
rapidly in height for a few days before dying. This is true for one variety, Oryza sativa
japonica. The variety Oryza sativa indica is much more tolerant to submergence.
Three genetically modified forms of O. sativa japonica, GMFA, GMFB and GMFC, were
made using different fragments of DNA taken from O. sativa indica.
The plants were then submerged for a period of 11 days. The heights of all the plants were
measured at the beginning and at the end of the submergence period.
[Adapted by permission from Macmillan Publishers Ltd, Xu et al. 2006. “Sub1A is an ethylene-response-factorlike gene that confers submergence tolerance to rice.” Nature. Vol 442. Pp 705–708. Copyright 2006.
http://www.nature.com/]
(a)
(i)
State which group of rice plants were the shortest at the beginning of the
experiment.
...........................................................................................................................
(1)
(ii)
Calculate the percentage change in height for the O. sativa japonica unmodified
variety during the submergence period. Show your working.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Explain how the error bars can be used to compare the results for O. sativa indica.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(c)
Deduce the general relationship between the growth of all the japonica varieties and
their stated tolerance level.
......................................................................................................................................
(1)
(d)
Outline the use of the binomial system of nomenclature in Oryza sativa.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
Answer:
(a)
(i)
(GMF) C
(ii)
(b)
(c)
(50  22)
× 100;
22
=127% ; (units required) (allow answers in the range of 127 to 127.3)
error bars show the range/variability/uncertainty of the data / OWTTE;
error bars/standard deviation about the same length for day 0 and day 11 /
spread of data (around the means) about the same;
overlapping bars indicate that there is no (significant) difference in the
data/ means;
68% of population within one standard deviation;
inversely proportional / the higher the tolerance, the less the
growth / vice versa
1
2
2 max
1
(d)
first name/Oryza for genus / second name/sativa for species;
(all) members of Oryza sativa share special/unique features;
two names make a unique combination to designate species / worldwide
recognizable nomenclature;
varieties (japonica and indica) have some (consistent) differences
(in tolerance);
2 max
Topic 5/Option G
The graph below shows the mean concentrations of CO2 in the atmosphere between 1960
and 2000
(a) Describe and explain these data. [6]
(b) Discuss the effect that increases in CO2 levels might have on the environment. [6]
(c) Outline ways by which emissions of CO2 may be reduced. [5]
Expression of ideas [3]
4. The table below shows animal production and respiration in kcal m-2 year-1 in five
ecosystems.
Net Community Productivity (NCP) = Net Primary Productivity (NPP) + Secondary
Productivity (SP)
Ecosystems:
A = Alfalfa grass field
B = young pine plantation
C = medium aged oak-pine forest
D = large river
E = mature tropical rainforest
(a) (i)
(ii)
Define the term community in ecology
[1]
Identify the ecosystem above which is likely to have the greatest species
diversity. Give a reason for your answer.
[2]
Ecosystem
Reason
(b)
State three factors that affect the primary productivity in the ecosystem above.
[1]
(c)
for ecosystem A
(i) Calculate the net primary productivity (NPP) and fill in the table [1]
(ii) Calculate the efficiency of conversion of GPP to NCP. Show your working.
[2]
(iii) Explain why ecosystem A has the highest NCP.
[2]
(iv) Explain why ecosystem E has the highest GPP but zero NCP.
[2]
(d)
State and explain the impact that:
(i)
(ii)
(iii)
a significant increase in the use of chlorofluorocarbons (CFCs) might have
on the GPP of the ecosystems.
[3]
Continuous acid deposition might have on the NPP in ecosystem B [3]
A 25% decrease in the area of ecosystem E might have on global
temperatures
[3]
3. Two areas of forest each contain 50 trees. The species composition of the two areas is as
follows.
(c) Simpson.s diversity index can be calculated by applying the formula below,
where: N = total number of organisms of all species,
n = number of organisms of a particular species.
[2] (i) Calculate Simpson.s diversity index for area B (showing your working).
................................................................. ....
............................................................. ........
............................................................... ......
.....................................................................
............................................................... ...
3.- The lizard population of an island was studied as follows. (HL only)
(a) During a three-day period 50 lizards were captured, marked and then released. Two
weeks later, on a second visit to the island, another 50 lizards were captured, of which 20
were already marked from the previous visit. Assuming that there have been no deaths or
hatchings, determine the approximate lizard population of the island. (HL only)
............................................................... ..........
.........................................................................
............................................................... ..........
............................................................... ..........
(b) Outline and evaluate a method for estimating the abundance of a named plant species in
a named ecosystem. (HL only)
............................................................... ..........
.........................................................................
............................................................... ..........
.........................................................................
............................................................... ..........
................................................................. ........
4. (a) Define the term diversity.
......................................................................
......................................................................
Topic 6
1.
Which process decreases when the human body temperature decreases?
A.
Blood flow to the internal organs
B.
Secretion of sweat
C.
Secretion of insulin
D.
Shivering
2.
3.
4.
5.
Which organ secretes enzymes that are active at a low pH?
A.
Mouth
B.
Pancreas
C.
Stomach
D.
Liver
Which vessel carries deoxygenated blood?
A.
The pulmonary artery
B.
The coronary artery
C.
The aorta
D.
The pulmonary vein
Which of the following structures help the absorption of food by the small intestine?
I.
Capillary networks
II.
Villi
III.
Microvilli
IV.
Membrane proteins
A.
I and II only
B.
II and III only
C.
II, III and IV only
D.
I, II, III and IV
Why do antibiotics kill bacteria but not viruses?
A.
Antibiotics stimulate the immune system against bacteria but not viruses
B.
Viruses have a way of blocking antibiotics
C.
Viruses are too small to be affected by antibiotics
D.
Viruses do not have a metabolism
6.
(a)
List two different types of blood cells.
...............................................................................................................................................
..............................................................................................................................................(1)
(b)
Explain why antibiotics are effective against bacteria but not viruses.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
..............................................................................................................................................(3)
(Total 4 marks)
7.
(a)
State the difference between an antigen and an antibody.
...............................................................................................................................................
...............................................................................................................................................
(1)
(b)
Explain antibody production.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
..............................................................................................................................................(3)
(c)
State two other substances, apart from antibodies, transported by the blood.
...............................................................................................................................................
............................................................................................................................................ (Total 5 marks)
Topic 9 (HL only)
Define transpiration
...............................................................................................................................................
...............................................................................................................................................
What are the key features of a monocotyledonous plant?
...............................................................................................................................................
...............................................................................................................................................
What are the key features of a dicotyledonous plant?
...............................................................................................................................................
...............................................................................................................................................
What are the three ways plants uptake water?
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How do terrestrial plants support themselves?
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What regulates the opening and closing of stomatal pores?
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Which hormone causes the closing of stomata?................................................................
What are the abiotic factors that affect the rate of transpiration?
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What is the effect of temperature on the rate of transpiration?
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What are the conditions required for the germination of a typical seed?
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What is phytochrome?
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What is fertilisation?
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What is seed dispersal?
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Why may dormancy be imposed on a seed?
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What it pollination?
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What are the structures in an flowering plant (angiosperm)?
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What is translocation?
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What are the adaptations of xyerophytes that help reduce transpiration?
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What is the effect of decreased humidity on the rate of transpiration?
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What is the effect of increased wind speed on the rate of transpiration?
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Draw a cross section of a leaf. Label all tissue types, cells, and layers. Annotate these labeled structures
with their functions.
Answers
Transpiration is the loss of water vapour from the leaves and stems of plants
1) Parallel veins,
2) Flower organs are in multiples of 3
3) One cotyledons
4) Fibrous, highly branching root structure
1) Net-like ventration/veins,
2) Flower organs are in multiples of 4 or 5
3) two cotyledons
4) Tap root structure with lateral roots
1) Mass flow/apoplast pathway - the water travels in the free space between the cell wall and the plasma
membrane, this is the main pathway
2) Diffusion/symplast pathway - the water travels through the cytoplasm and cytoplasmic connections. This
is not a main pathway because the organelles create resistance against water flow.
3) Osmosis- how individual plant cells absorb water. The water travels from vacuole to vacuole and is
driven by the gradient in osmotic pressure.
1) Cell strength (parenchyma and collenchyma)
2) Cell turgidity
3) Lignified xylem vessels - (walls of xylem vessels are strengthened by the chemical lignin)
Guard cells
Abscisic acid
1) Light
2) Temperature
3) Wind
4) Humidity
Higher temperatures increase the rate of transpiration because it increases the rate of evaporation which
creates a higher vapour potential in the free air space of the leaf.
- Oxygen for aerobic respiration
- Water to metabolically activate cells
- Temperature for the optimal functions of enzymes.
Fertilisation is the fusion of a male gamete (pollen grain) and a female gamete (ovary) to form a zygote.
Phytochrome is a highly reactive blue-green pigment (photoreceptor). There are two types: phytochromered (blue pigment, 660nm) and phytochrome-far-red (blue-green pigment, 730nm).
Seed dispersal is the carrying of the seed (product of fertilised ovary) away from the vicinity of the parent
plant for reasons to do with competition.
- Incomplete seed development
- The presence of plant growth regulators
- An impervious seed coat which is eventually made permeable (e.g. through abrasion)
Seed dispersal is the carrying of the seed (product of fertilised ovary) away from the vicinity of the parent
plant for reasons to do with competition.
Pollination is the transfer of pollen from the anther to the stigma
Stigma, style, ovary, sepal, petals, anthem and filament.
Translocation is the movement of sugars and amino acids in the phloem.
- A thick, waxy cuticle helps prevent water loss
- Deep roots exploit a deep water table in the soil
- A reduced number of stomata reduces the outlets through which water vapour can diffuse
- Layer of hairs on epidermis traps moist air and reduces the rate of diffusion
Decreased humidity increases the rate of transpiration because there is less water vapour in the area
surrounding the leaf. This means that there is a higher concentration gradient between the inside and
outside of the leaf.
Decreased humidity increases the rate of transpiration because there is less water vapour in the area
surrounding the leaf. This means that there is a higher concentration gradient between the inside and
outside of the leaf.leaf. This enhances the difference in the concentration gradient between the inside and
the outside of the leaf.
Increased wind speed increases the rate of transpiration. The wind moves any water vapour that was
accumulating around the exterior of the
Diagram of Leaf Cross Section