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Figures
Words
2013 Trial Examination
Letter
STUDENT NUMBER
SUPERVISOR TO ATTACH PROCESSING LABEL HERE
BIOLOGY
Units 3 & 4 - Written examination
Reading time: 15 minutes
Writing time: 2 hours and 30 minutes
QUESTION & ANSWER BOOK
Structure of book
Section Number of
questions
Number of questions
to be answered
Number of
marks
Suggested times
(minutes)
A
40
40
40
30
B 11 11 70 70
Total 110 150
Students are permitted to bring into the examination room: pens, pencils, highlighters,
erasers, sharpeners and rulers
Students are NOT permitted to bring into the examination room: blank sheets of paper
and/or white out liquid/tape.
No calculator is permitted in this examination.
Materials supplied
Question and answer book of 33 pages.
Instructions
Print your name in the space provided on the top of this page.
All written responses must be in English.
Students are NOT permitted to bring mobile phones and/or any other unauthorised
electronic communication devices into the examination room.
2013 BIOLOGY EXAM
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SECTION A – Multiple-choice questions
Instructions for Section A
Select the response that is most correct for the question. A correct answer scores 1, an
incorrect answer scores 0. Marks are not deducted for incorrect answers. If more than 1
answer is completed for any question, no mark will be given.
Question 1 Which of the following is produced as the result of hydrolysis?
A. Amino acids being converted into a protein
B. Fatty acids being converted into a lipid
C. Cellulose being converted into glucose
D. ADP being phosphorylated to produce ATP
Question 2 Which of the following molecules is a carbohydrate?
A. C3H7O2N
B. C16H32O16
C. C13H26O2
D. C20H40O2
Question 3 In a double stranded segment of DNA the number of cytosine and guanine bases will be identical.
The best reason for this is:
A. Guanine always follows cytosine on each strand
B. The number of all bases in a DNA strand are always identical
C. Guanine and cytosine alternate on the strands of DNA
D. Cytosine on one strand binds to guanine on the second strand
Question 4 Bacterial and fungal cells both have cell walls. Which of the following identifies the difference
between them?
A. Bacterial walls are carbohydrate based, fungal walls are protein based
B. There is no difference between the cell walls of these organisms
C. Both types of cell walls are carbohydrate based
D. Bacterial walls are made of peptidoglycan and fungal walls of chitin
SECTION A - continued
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Use the following information to answer questions 5 and 6
The diagram below shows an overview of a reaction that occurs in a living organism.
Question 5 Which of the following is correct about this reaction?
A. It is anabolic and endergonic
B. It is anabolic and exergonic
C. It is catabolic and endergonic
D. It is catabolic and exergonic
Question 6 The chemical nature of compound C is that it is:
A. Carbohydrate
B. Lipid
C. Nucleic Acid
D. Protein
Question 7 A student placed some red blood cells into a solution. Five minutes later they observed the cells
using a light microscope and drew the following diagram.
Based upon this information which of the following conclusions can be made?
A. The cells have crenated
B. The solution was hypotonic
C. The cells are flaccid
D. The cells have plasmolysed
SECTION A - continued
TURN OVER
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Question 8 Which of the following must be present in order for diffusion to occur?
A. ATP
B. A living cell
C. A concentration difference
D. A semi permeable membrane
Question 9 A living cell carries out a reaction that produces NADH, ATP and pyruvate. This reaction must
be:
A. Aerobic respiration
B. Glycolysis
C. Krebs Cycle
D. Photosynthesis
Question 10 Which of the following occurs to NADH during the process of cellular respiration?
A. It is degraded by enzymes to produce NAD+
B. It moves from the mitochondria to the cytosol
C. It is converted into ATP
D. It delivers hydrogen ions to the electron transport chain
Question 11 Plants carry out a series of chemical reactions which enable them to produce organic compounds.
If a plant’s leaves wilt the production of organic compounds decreases. The reason for this is:
A. Chlorophyll denatures when leaves wilt
B. Light is no longer able to reach the chlorophyll
C. Stomata close preventing carbon dioxide from entering the leaf
D. Water is no longer able to reach the leaf
Question 12 After sugar peas are picked they are immediately boiled and then snap frozen in order to preserve
their sweetness. Which of the following best explains why these processes are carried out?
A. The enzymes responsible for converting sugars into starch cease to function under these
conditions
B. The enzyme responsible for breaking down the sugars ceases to function after the peas
were picked
C. The boiling processes denature starches which causes the loss of flavour in peas
D. The process of boiling increases the concentration of sugars in the peas
SECTION A - continued
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Question 13 A student completed an experiment which involved establishing the rate of an enzyme catalysed
reaction under various conditions. After completing the experiment the student used their results
to produce the following graph:
Which of the following best explains why the shape of the graph changed?
A. The student changed the pH of the conditions the enzyme was exposed to
B. The shape of the active site of the enzyme gradually changed
C. The substrate was completely used up during the reaction
D. The concentration of the enzyme was constant whilst substrate concentration was
increased
Question 14 Anti-diuretic hormone (ADH) is a steroid hormone secreted by the hypothalamus. It acts upon the
nephron of the kidneys promoting the reabsorption of water. ADH is secreted into the circulatory
system, but only acts upon the collecting tubule. ADH is an example of
A. A neurohormone
B. A paracrine hormone
C. A phagosome
D. A pheromone
Use the following information to answer questions 15 and 16
A chemical is secreted into the circulatory system. It is transported by the blood and is taken up
by an organ which then begins to produce and secrete enzymes.
Question 15 The chemical is most likely to be:
A. An enzyme
B. A hormone
C. DNA
D. A promoter
SECTION A - continued
TURN OVER
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Question 16 The term used to describe the series of events is:
A. Feedback
B. Homeostasis
C. Signal transduction
D. Transcription
Question 17 Which of the following correctly identifies the means by which nervous impulses are transmitted?
A. The presence of myelin increases the diameter of a neuron and slows impulse
transmission
B. Neurotransmitters are actively transported across the synapse
C. Ions are sequentially transported across the membrane of the axon
D. For an impulse to occur a stimulus must exceed resting potential
Question 18 Which of the following are chemical contributions to the body's first level of defence against
disease?
A. Sebum
B. Low blood pH
C. Interferon
D. Cytokines
Question 19 Which of the following cells is located in lymph nodes and plays a role in cell mediated
immunity?
A. Mast cells
B. Natural killer cells
C. Neutrophils
D. Thrombocytes
Question 20 Which of the following cells express class 1 MHC markers?
A. All nucleated cells
B. Lymphocytes only
C. Macrophages only
D. Phagocytic cells only
SECTION A - continued
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Question 21 A polypeptide found in the cytoplasm of a cell contains 20 amino acids. How many nucleotides
would be required in the mRNA for this polypeptide to be translated?
A. 20
B. 40
C. 60
D. 63
Question 22 An anticodon has the sequence GUA. The original sequence of DNA would be:
A. GUA
B. GTA
C. CAU
D. CAT
Question 23 It is normal for the combination of sex chromosomes in Humans to be either XX or XY, however,
sometimes abnormal combinations such as X, XXY or XXX may occur. These unusual
combinations occur due to:
A. Translocation during meiosis
B. A genetic mutation which targets sex chromosomes
C. Nondisjunction of chromosomes during meiosis
D. Independent assortment of chromosomes during meiosis
Question 24 A plant that is pure breeding for dominant traits is crossed with a plant that is purebreeding for
recessive traits. There are two phenotypes in the parental generation, one phenotype in the F1
generation and four phenotypes in the F2 generation. This must be an example of
A. A dihybrid cross
B. A monohybrid cross
C. Co-dominance
D. Polygenic inheritance
SECTION A - continued
TURN OVER
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Question 25 Colour blindness is an X-linked recessive condition. A woman with normal vision who had a
colour blind father marries a man with normal vision. The chance that her sons will be colour
blind is:
A. 0%
B. 25%
C. 50%
D. 100%
Question 26 A particular breed of dogs can have either smooth hair or wiry hair. Hair texture is a monogenic
trait. A dog breeder wishes to establish a line of dogs that are pure breeding for smooth hair. He
performs a cross between a male dog with smooth hair and three different female dogs, each of
which has 10 puppies over several litters. The table below shows the phenotype of the female
dogs and of their offspring.
Dog Phenotype of the dog Number of smooth haired
offspring
Number of wiry haired
offspring
1 Smooth hair 10 0
2 Smooth hair 8 2
3 Wiry hair 5 5
Based upon the information provided which of the dogs must be heterozygous?
A. The male and females 1 and 3 only
B. The male and female 2 only
C. The male and female 3 only
D. Females 2 and 3 only
Question 27 A test is completed to determine the sequence of an allele that codes for a normal trait. It is then
compared to the allele that codes for a genetic condition.
The sequence for the first allele is: AGC TGA GGG TTC
The sequence for the second allele is: AGC TGA CGG TTC
The term for this type of mutation is:
A. Frameshift
B. Genomic
C. Point
D. Selective
SECTION A - continued
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Question 28 Which of the following reasons explains the importance of crossing over?
A. More genetic material is available to the daughter cells
B. The daughter cells will be able to produce more proteins
C. It increases the chance that all daughter cells will be genetically different
D. It provides the mechanism for separating the homologous chromosomes
Question 29 The Macaroni penguin is the most abundant species of penguin with a range that extends from
sub-Antarctica to the Antarctic Peninsula. Macaroni Penguins can have either black faces or
white faces. The majority of Macaroni Penguins in most locations have a black face, however, a
population of Macaroni Penguins located on Macquarie Island (located off the coast of Australia)
all Macaroni Penguins have white faces.
This is most likely to be the result of:
A. Founder effect
B. Gene flow
C. Population bottleneck
D. Speciation
Question 30 Skin colour in humans is a polygenic trait. This means that skin colouration is determined by:
A. many genes all contributing to the production of a single protein
B. the expression of a single gene
C. the effect of the environment on skin cells
D. different genes at different loci acting collectively
Question 31 Some students were asked to provide a definition of homologous structures. Three of the
definitions provided are shown below:
I Homologous structures occur in pairs
II Homologous structures occur in organisms that share recent common ancestry
III Homologous structures have the same genes in the same order
Which of the following are correct?
A. I and II only
B. II and III only
C. II only
D. I and III only
SECTION A - continued
TURN OVER
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Question 32 Two of the most common frogs in North America are the wood frog, Rana sylvatica and the
leopard frog, Rana pipiens. The females of both species produce masses of eggs in a jellylike
substance. These are subsequently fertilised by the males. If the eggs of one species are fertilised
by the sperm of the other then the embryos either do not develop or do not reach adulthood.
The process which prevents reproduction between these two species is known as:
A. Gamete mortality
B. Postzygotic isolation
C. Prezygotic isolation
D. Speciation
Question 33 The sequence of events that lead to speciation occuring is:
A. Reproductive isolation geographical barrier genetic mutations
B. Genetic mutations geographical barrier different selection pressures
C. Different selection pressures Geographical barrier genetic mutations
D. Geographical barrier reproductive isolation different selection pressures
Question 34 Human proteins are injected into a rabbit which then produces anti-human antibodies. These
antibodies are collected and placed into four test tubes. Each tube has protein from one of the four
species listed below added.
The table below shows the % difference between human DNA and that of four other species.
SPECIES % DIFFERENCE IN DNA
1 1.8
2 3.9
3 18.5
4 8.2
In which test tube will the greatest amount of coaggulation occur?
A. 1
B. 2
C. 3
D. 4
SECTION A - continued
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Question 35 The table below shows the presence or absence of features in four different species.
This information was used to produce the cladogram shown below
Which of the following is most correct?
A. A represents the newt
B. B represents having hair
C. C represents the earthworm
D. D represents having legs
SECTION A - continued
TURN OVER
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Question 36 Identical twins that were separated at birth are considered to be ideal for studying certain aspects
of genetic inheritance. For which of the following studies would these identical twins be most
useful?
A. The effect of environment upon phenotype
B. The effect of genes upon phenotype
C. The effect of genes upon environmental conditions
D. The effect of separation upon environmental conditions
Question 37 Genetic variation in a population can occur due to the process of gene flow. This term refers to:
A. Genetic material being transferred between chromosomes
B. Specific traits being passed from parents to their offspring
C. The production of proteins due to the processes of transcription and translation
D. Individuals migrating between two different populations
Question 38 Index or indicator fossils are one form of evidence used to support the theory of evolution. Which
of the following attributes determine their usefulness?
A. They must show gradual change over a period of time
B. They must be located in a small geographical area over a long period of time
C. They must be present in large numbers over a short period of time
D. They must contain a known amount of carbon compared to other living organisms
Question 39 Which of the following correctly identifies the purpose of restriction enzymes?
A. They bind to and cut DNA at specific recognition sequences
B. They restrict the function of other enzymes
C. The restrict the rate at which chemical reactions can occur
D. They speed up the rate of DNA replication
SECTION A - continued
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Question 40 One of the most common applications of gene cloning involves splicing the gene for the
production of human insulin into a plasmid. A gene for antibiotic resistance is also inserted into
the plasmid before it is taken up by a bacterium. The purpose of including the antibiotic
resistance gene is:
A. To identify the recombinant plasmid
B. To identify the transformed bacteria
C. To prevent the gene coding for human insulin from being broken down by the bacteria
D. To produce insulin resistance in bacteria
END OF SECTION A
TURN OVER
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SECTION B - Short-answer questions
Instructions for Section B
Answer all questions in the spaces provided.
Question 1 (5 marks)
The diagram below shows several molecules that are involved in the process of protein synthesis.
a. Identify the processes that are responsible for the production of molecules 2 and 4. 1 mark
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b. Identify two ways in which molecules 1 and 2 differ. 1 mark
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SECTION B – Question 1 - continued
Molecule 1
Molecule 3
Molecule 4
Molecule 2
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c. Identify the monomers that are used to construct molecule 4. 1 mark
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d. Explain why the three-dimensional structure of a protein with a single polypeptide chain
differs from a protein that is constructed out of four polypeptide chains. 2 marks
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SECTION B - continued
TURN OVER
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Question 2 (7 marks)
The diagram below shows a signalling molecule about to bind to a receptor on the external
surface of a plasma membrane.
a. Two students are discussing the type of signalling molecule involved. Student 1 states this
is a protein hormone and student 2 states that it is a steroid. Which student is correct?
Provide a reason to support your answer. 2 marks
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b. Identify the type of chemical compound that is acting as the receptor. 1 mark
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SECTION B – Question 2 - continued
Receptor
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c. Some types of signal transduction are mediated by second messengers. Briefly explain the
role of second messengers. 1 mark
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d. Identify a specific second messenger you have studied. 1 mark
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e. Explain how water soluble and lipid soluble substances differ in the way in which they
interact with the plasma membrane. 2 marks
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SECTION B – continued
TURN OVER
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Question 3 (4 marks)
The diagram represents the structure of a chloroplast.
a. Identify structures 1 and 2. Explain the function of each structure. 3 marks
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b. There is a small space called a lumen within the thylakoid membrane. What is the
importance of this area? 1 mark
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SECTION B – continued
Structure 2 Structure 1
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Question 4 (7 marks)
A group of scientists set up an experiment to test the rate of aerobic cellular respiration.
This experiment involved the use of four sealed conical flasks. Distilled water, two drops of
ammonia and phenol red indicator were placed into flasks 1, 3 and 4. A mouse was placed into
flask 3. If carbon dioxide is produced during the course of the experiment it will dissolve in the
water producing carbonic acid.
Phenol red is an indicator that is yellow under acidic conditions and pink under basic conditions.
The fluid in the three flasks containing water is initially pink.
a. After 24 hours the solution in flasks 3 and 4 remained pink while the solution in flask 1
had turned yellow. Explain why the colour change occurred in flask 1. 2 marks
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SECTION B – Question 4 - continued
TURN OVER
1 2 3 4
Direction of air flow
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b. Explain why the extent of colour change in flask 1 can be used to estimate the rate of
aerobic respiration. 2 marks
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c. The process of aerobic respiration is a metabolic pathway which includes several stages,
each of which consists of a variety of reactions. Which stage is responsible for producing
the greatest amount of ATP? Explain. 2 marks
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SECTION B – Question 4 - continued
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d. Aerobic respiration is enzyme catalysed. The enzymes that catalyse this reaction are
highly specific. Explain the advantage of specificity. 1 mark
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Question 5 (7 marks)
Plasmodium falciparum is a species of protozoa that is the main cause of malaria in humans. It is
important for organisms that repeatedly infect a single host or that target long lived hosts are able
to evade immune responses. One virulence strategy employed by P. falciparum is the ability to
alter proteins located on their surface.
a. What is the term used to describe the ability to alter surface proteins? 1 mark
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b. Explain in detail the specific and non-specific responses that will happen when an
individual is initially exposed to foreign proteins such as those produced by P.
falciparum. 2 marks
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SECTION B – Question 5 - continued
TURN OVER
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c. What will happen to the speed and strength of the specific immune response if a person is
exposed to P. falciparum a second time? Explain why this will occur. 2 marks
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d. There is currently no vaccine for P. falciparum. Use the information provided to explain
why this is the case. 1 mark
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e. Discuss one method by which organisms such as P. falciparum are able to alter their
surface proteins. 1 mark
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SECTION B – continued
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Question 6 (7 marks)
Conditions such as asthma are caused by an individual having overly sensitive cholinergic
receptors which cause the muscles of the airways to contract when they shouldn’t. This prevents
the person from breathing out. It is thought that the contraction of the muscles is facilitated by
mast cells and eosinophils releasing chemicals into the airways.
a. What substance is secreted by the mast cells? 1 mark
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b. Mast cells also play a role in hypersensitivity reactions. Explain how mast cells are
involved in hypersensitivity reactions. 2 marks
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c. Mast cells also play a role in the inflammatory response. Explain why histamine is
perceived to play a positive role in the inflammatory response, but a negative role in
hypersensitivity reactions. 2 marks
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SECTION B – Question 6 - continued
TURN OVER
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d. Is the action of mast cells specific or non-specific? Explain. 2 marks
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Question 7 (5 marks)
A strain of wheat has a long stem. It produces a high yield of seeds, however, this strain is prone
to lodging, the collapse of top heavy plants as shown in the diagram below. A second strain of
wheat produces less seeds but has a shorter stem. A group of scientists wish to produce a strain of
wheat plants that do not experience lodging but still produce a high yield of seeds.
An initial cross was performed using a pure breeding example of each strain. All of the F1
generation had a short stem and a high yield of seeds.
a. Assign appropriate allele symbols for these traits. What are the genotypes of the parents?
1 mark
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SECTION B – Question 7 - continued
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b. What is the genotype of the F1 offspring? 1 mark
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c. Will the F1 offspring breed true in the F2 generation? Provide a reason to support your
answer. 2 marks
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d. What term is used to describe this process of humans breeding a particular trait (such as
short stems and high yield of seeds in wheat)? 1 mark
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SECTION B – continued
TURN OVER
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Question 8 (7 marks)
The diagram below shows the inheritance of a genetically inherited condition
a. What is the mode of inheritance for this trait? Use the data provided to support your
answer. 3 marks
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SECTION B – Question 8 - continued
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b. Individuals II-3 and II-4 have another child who is unaffected by the trait. What is the
probability that this child will be heterozyous? Provide a reason to justify your answer.
2 marks
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c. What is the probability that individual II-1 carried the allele for this trait? Use the data
provided to support your answer. 2 marks
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SECTION B – continued
TURN OVER
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Question 9 (11 marks)
Scientists have been investigating a species of freshwater fish Milyeringa verita, which occurs in
Australia, and another species, Typhelotris paulini, which occurs in Madagascar. Both species of
fish are small in size, lack eyes, and live in freshwater caves. It has been found that both species
are descended from a common ancestor with geographical separation occurring approximately
100 million years ago.
a. Is this an example of convergent evolution or divergent evolution? Provide a reason to
support your answer. 2 marks
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b. Although these fish have many similarities, DNA analysis has proved that they are
members of different species. Explain how this occurred. 2 marks
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SECTION B – Question 9 - continued
Madagascar
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In a separate study scientists investigated the Mexican tetra, a fish living in freshwater that has
normal eyes and a silvery grey body, and the Mexican cave fish, which has a colourless body and
eyes covered by skin flaps.
c. The study found that the tetra was able to migrate into the caves and successfully
interbreed with the cavefish and vice versa. The offspring produced are able to reproduce.
What is the significance of this finding? Would it be appropriate for both types of fish to
be given the scientific name Astyanax mexicanus? Explain. 2 marks
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d. The scientists found that the cavefish populations which had the greatest number of
immigrants had the greatest genetic diversity. Is this result as expected? Explain. 2 marks
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SECTION B – Question 9 - continued
TURN OVER
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e. It has also been found that despite immigration by sighted fish, the population of cavefish
retain the sightless adaptation. Provide a plausible reason for this. 1 mark
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f. The olm, Proteus anguinus, is an amphibian that is found in freshwater caves in South-
eastern Europe. Like the fish located in Australia, Madagascar and Mexico the olm is also
colourless and has undeveloped eyes. Explain why this has occurred. 2 marks
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SECTION B – continued
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Question 10 (5 marks)
Huntington’s disease is an autosomal dominant genetic disease caused by a mutation to a gene
located close to the end of chromosome 4. The cause has been traced to the presence of a higher
than normal number of CAG repeats (e.g. CAGCAGCAG) in the gene. Normally this gene would
have between 11 and 30 CAG repeats, however the form of the gene which causes Huntington’s
disease has over 40 CAG repeats.
A man whose mother had the condition and believes he is beginning to experience the symptoms
of Huntington’s disease decides to undergo genetic testing. His wife and son are also tested at the
same time. The diagram below represents the results of the genetic test.
a. Explain why DNA moves in the direction indicated. 1 mark
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SECTION B – Question 10 – continued
TURN OVER
Man Woman Son
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b. Which bar identifies the allele for Huntington’s disease? Provide a reason to support your
answer. 2 marks
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c. Which of the individuals tested will develop Huntington’s disease? Provide a reason to
support your answer. 2 marks
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Question 11 (5 marks)
In March 2012 a group of scientists published information about a previously unknown type of
hominin subsequently referred to as Red Deer People. Four sets of skeletal remains were
discovered in Red Deer and Longlin caves in China. These fossils have been dated at between
14500 and 11500 years old.
a. Explain why caves are good environments for fossilisation. 1 mark
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SECTION B – Question 11– continued
2013 BIOLOGY EXAM
© TSSM 2013 Page 33 of 33
b. Identify an absolute dating technique that could have been used to establish the age of
these fossils. 1 mark
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c. The Red Deer People had thick skull bones and distinctive features including a flat face,
broad nose, prominent brow ridges, large molars and a moderate sized brain. Based solely
on this information should the Red Deer People be considered to be ancient or modern?
1 mark
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d. These fossils are referred to as being transitional. Explain the importance of this type of
fossil. 1 mark
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e. Currently scientists are reluctant to state that the Red Deer People are a separate hominin
species. This is partially due to the fact that all attempts to extract mitochondrial DNA
have been unsuccessful. Explain the importance of mitochondrial DNA in determining the
extent of relatedness between different species. 1 mark
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END OF QUESTION AND ANSWER BOOK
