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Name: _______________________________________________
Topic 9
Date:
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Questions
Q1.
The scientific article you have studied is adapted from articles in New Scientist.
Use the information from the article and your own knowledge to answer the following questions.
(a) Suggest why 'incredibly efficient cellular mechanisms' can increase the chance of obesity (paragraphs
4 and 5).
(2)
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(b) A larger VO2max means more oxygen can enter a mitochondrion and therefore more energy can be
released from fuel (paragraph 8).
Name two substances, other than oxygen, that need to enter the mitochondrion to enable energy to be
released from fuel.
(2)
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(c) Describe the structure of glycogen (paragraph 11).
(3)
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(d) Using the information in paragraphs 12 to 14, explain how lowered testosterone levels may help a
cyclist to race harder on successive days.
(3)
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(e) Explain why Coyle suggests that greater muscle efficiency may be linked to an increase in the
percentage of slow twitch muscle fibres (paragraph 20).
(2)
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*(f) Suggest how 'the development of a leak in a specific class of calcium channel in muscle cells' can
lead to muscle fatigue (paragraph 23).
(4)
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(g) The ACE gene codes for the synthesis of angiotensin converting enzyme (ACE) (paragraph 25).
Complete the table by naming two nucleic acids involved in each of the processes described.
(2)
(h) A variant of the APOE gene could put individuals at increased risk in contact sports. DNA profiling is a
technique that can be used in genetic screening.
Suggest how DNA profiling could be carried out to identify this variant of the APOE gene (paragraph 27).
(4)
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(i) The titin gene produces a protein that attaches to myosin in a sarcomere (paragraph 30).
Place a cross (
) in the box that identifies myosin shown in the diagram.
(1)
A
B
C
D
(j) The colder the water Japanese Ama divers swim in, the higher their resting metabolic rate (paragraph
50).
Suggest and explain why this might be an advantage to these divers.
(3)
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(k) Pugh noticed the effects of climate change (paragraph 53).
Name two greenhouse gases that contribute to climate change. Give one source of each of these gases.
(2)
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(l) Using the information in paragraph 55, calculate the percentage increase in Pugh's core body
temperature due to his "anticipatory thermogenesis".
Show your working.
(2)
Answer = .............................................................. %
(Total for question = 30 marks)
Q2.
A student was interested to find out how his heart rate would vary throughout the day.
He wore a heart rate monitor from the time he woke up until the time he went to bed.
The graph shows the data collected and some of the student's activities during the day.
Calculate the rate of increase in the student's heart rate between 6 am and 8 am.
(2)
Answer ...........................................................
Q3.
A defect in the cone cells of the retina can result in colour blindness.
(a) Which is the visual pigment found in cone cells?
(1)
A
iodopsin
B
opsin
C
retinol
D
rhodopsin
(b) The table below shows the distribution of different cones involved in colour blindness.
(i) The population of London is 12 million, of which 55% are men.
Calculate the number of men in London who are colour blind.
(3)
Answer ...........................................................
(ii) The allele for one defect in cone cells is recessive and carried on the X chromosome.
Explain why more men than women are colour blind.
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(iii) L-cones respond to long wavelengths of light.
M-cones respond to medium wavelengths of light.
S-cones respond to short wavelengths of light.
The visible light spectrum is shown below.
Analyse the data to explain why red/green colour blindness is the most common throughout the
population.
(4)
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(Total for question = 10 marks)
Q4.
The graphs below show the conduction velocity and diameter of myelinated and unmyelinated axons.
(i) Calculate the time it would take for a nerve impulse to travel 80 cm in a myelinated axon with a
diameter of 7 μm.
(2)
Answer ........................................................... s
*(ii) Analyse the data to explain the conduction velocity in the myelinated and the unmyelinated
axons.
(6)
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(Total for question = 8 marks)
Q5.
A student was interested to find out how his heart rate would vary throughout the day.
He wore a heart rate monitor from the time he woke up until the time he went to bed.
The graph shows the data collected and some of the student's activities during the day.
The student noticed that the graph showed a change in his heart rate while he was playing computer
games.
He designed an investigation to find out how different computer games affect heart rate.
The student played one computer game and recorded the increase in his heart rate.
He then played four other different computer games and again recorded the increase in his heart rate.
He repeated this on six different occasions throughout the week.
(i) Explain how the design of the student's investigation could be improved.
(4)
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(ii) Sketch a suitable graph that the student could use to present the results of his investigation.
(2)
Q6.
The diagram below shows a simple respirometer used by a student to measure the rate of respiration of a
small invertebrate called a woodlouse.
The rate was measured by observing the distance the indicator fluid moved in a known time.
(a) Give one way in which the student could modify the procedure to obtain a better measurement of the
rate of respiration.
(1)
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(b) Explain what would happen to the indicator fluid after five hours if a culture of green algae was added
to the container and the tube was completely covered in light-proof paper.
(4)
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(c) (i) The student wanted to compare the rate of respiration of a mouse with that of a woodlouse.
Explain how you could modify the procedure used to measure the rate of respiration of the woodlouse
so that it could be used to compare with the rate of respiration of a mouse.
Your answer should explain the reasons for the modifications and include reference to the ethical
treatment of the animal, and show how you could produce valid results.
(5)
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(ii) Comment on how the results you would expect to obtain for a mouse would differ from the results
for a woodlouse.
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(Total for question = 12 marks)
Q7.
The photomicrograph below shows myelinated neurones.
Magnification ×226
(a) The time taken for an impulse to travel between two electrodes placed at the points labelled A and B
was measured as 0.02 milliseconds.
Calculate the speed of the impulse.
(3)
Answer ........................................................... ms−1
(b) The neurones of the retina are not usually myelinated. However in some eye conditions, myelination
does occur.
Explain why the presence of myelinated neurones in the retina might mean that a clear image will not
be formed.
(3)
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(Total for question = 6 marks)
Q8.
(a) The diagram below shows a motor neurone.
(i) Name the structure labelled P.
(1)
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(ii) Place a cross
neurone.
in the box to identify the direction of the nerve impulse in the axon of this motor
(1)
(b) Eugenol is a drug that inhibits the movement of sodium ions through the cell surface membranes of
sensory neurones.
The table below shows the effect of eugenol concentration on the percentage inhibition of sodium ion
movement.
(i) Describe the effect of eugenol on the percentage inhibition of sodium ion movement.
(2)
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(ii) Using information from the table, calculate the percentage inhibition of sodium ion movement at a
concentration of eugenol of 0.8 mmol dm−3.
Show your working.
(2)
Answer.....................................................................%
*(c) Eugenol can be used to reduce pain.
Suggest an explanation for how eugenol affects the movement of sodium ions and reduces pain.
(6)
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(Total for Question = 12 marks)
Q9.
The photograph below shows a desert mammal.
Some desert mammals do not drink water. They obtain water from the food they eat and from respiration.
(a) Explain how water is formed in respiration.
(2)
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(b) The table below shows the percentage of plant roots and insects in the diet of two different species of
desert mammal.
(i) The desert mammals eat 8 g of food in one day. Calculate how many more grams of insects are
eaten by T. indica than by M. hurrianae.
(2)
Answer ........................................................... g
(ii) Which species has kidneys that will produce the most concentrated urine?
Justify your answer.
(2)
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(c) Which row of the table below shows the correct changes to the concentration of sodium ions as fluid
moves along the descending and ascending loop of Henle?
(1)
(d) The concentration of urine is controlled by osmoreceptors and the secretion of ADH.
Which row of the table below shows the location of the osmoreceptors and the correct level of ADH
secretion in a desert mammal that produces concentrated urine?
(1)
(e) Explain how the nephrons of desert mammals enable them to survive in a dry environment.
(4)
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(Total for question = 12 marks)
Mark Scheme
Q1.
Q2.
Q3.
Q4.
Q5.
Q6.
Q7.
Q8.
Q9.