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Ousedale School
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Biology Foundation Half Term Paper
Name: ________________________
Class: ________________________
Date: ________________________
Time: 75 minutes
Marks: 75 marks
Comments:
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Q1.The diagram below shows the water balance for a person on a cold day.
The numbers show the volume of water, in cm3, the person’s body gained and lost.
(a) (i) How much water was lost from the body on the cold day?
Draw a ring around the correct answer.
(1)
(ii) The volume of water gained by the body should balance the volume of water lost from the body.
How much water should the person have drunk to keep the balance?
...................................................................................................................
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Volume of water = ............................... cm3
(2)
(b) (i) Name the process by which water is lost from the skin.
................................................................................................................... (1)
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(ii) Why does the body need to lose water from the skin?
...................................................................................................................
................................................................................................................... (1)
(c) The next day was a hot day. The person gained the same volume of water and did the same activities.
(i) What effect did the increase in temperature have on the volume of water the person lost?
Tick (✔) one box.
Less water was lost through the skin.
More water was lost through the skin.
More water was lost in faeces.
(1)
(ii) What effect would the increase in temperature have on the volume of urine the person lost?
Draw a ring around the correct answer.
(1)
(Total 7 marks)
Q2.Some people with diabetes do not produce enough insulin to keep their blood glucose at the correct levels.
(a) (i) Which organ monitors blood glucose levels?
Tick (✔) one box.
liver
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pancreas
skin
(1)
(ii) What effect does insulin have on glucose in the blood?
Tick (✔) one box.
Insulin causes glucose to move into the cells.
Insulin increases the amount of glucose in the blood.
Insulin converts glucose to starch.
(1)
(b) Some people with diabetes inject insulin several times a day.
There are different types of insulin.
The graph shows some information about three different types of insulin, A, B and C.
(i) Which type of insulin, A, B or C, should a person with diabetes inject just before eating a meal high in carbohydrates?
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.......................................................
Give a reason for your answer.
...................................................................................................................
................................................................................................................... (2)
(ii) A woman with diabetes has a blood glucose level of 12 mmol per dm3 of blood.
The woman’s normal blood glucose level is 6 mmol per dm3.
The woman will need to inject insulin to lower her blood glucose level.
For each unit of insulin injected the blood glucose level will fall by 3 mmol per dm3.
How many units of insulin does the woman need to inject to bring her blood glucose level down to the normal level?
...................................................................................................................
Number of units = ....................................... (1)
(c) Some people have pancreas transplants to treat diabetes.
Give one possible disadvantage of a pancreas transplant.
Tick (✔) one box.
The pancreas could be rejected.
The patient will need to inject insulin every day.
The patient’s blood glucose levels may rise and fall too much.
(1) (Total 6 marks)
Q3.Glands in the body produce hormones.
(a) Use words from the box to label gland A and gland B on the diagram below.
Adrenal Pancreas Pituitary Testis
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Thyroid
(2)
(b) Which gland produces oestrogen?
Tick one box.
Ovary
Pancreas
Testis
Thyroid
(1)
(c) Table 1 shows some methods of contraception.
Table 1
Type of
contraception
Percentage (%) of pregnancies prevented
Oral pill >99
Implant 99
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Condom 98
Diaphragm <96
Which method of contraception in Table 1 is least effective at preventing pregnancy?
............................................................................................................................. (1)
(d) Which method of contraception in Table 1 will protect against sexually transmitted diseases like HIV?
............................................................................................................................. (1)
(e) Another method of contraception is called the intrauterine device (IUD).
There are two main types of IUD:
• copper
• plastic.
Both types of IUD are more than 99% effective.
Look at Table 2.
Table 2
Copper IUD Plastic IUD
How the IUD works
• releases copper
• copper changes the fluids in the uterus to kill sperm
• releases a hormone
• hormone thickens mucus from the cervix so the sperm have more difficulty swimming to the egg
Benefits
• prevents pregnancy for up to 10 years
• can be removed at any time
• can be used as emergency contraception
• prevents pregnancy for up to 5 years
• can be removed at any time
Possible
• very painful periods
• heavy periods or periods which last for a
• painful periods
• light periods or no periods
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side effects long time
• feeling sick, back pain
• feeling sick, headaches, breast pain, acne
• hormones may affect mood
• ovarian cysts
Evaluate the use of the plastic IUD as a contraceptive compared to the copper IUD.
Use the information in Table 2.
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............................................................................................................................. (4)
(Total 9 marks)
Q4. The photographs show four ways of farming.
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Growing wheat by Eileen Henderson [CC-BY-SA-2.0], via Wikimedia Commons. Keeping Sheep outside by Andrew Smith [CC-BY-SA-2.0], via Wikimedia Commons. Keeping Pigs outside by David Williams [CC-BY-SA-2.0], via Wikimedia Commons. Keeping Pigs inside supplied by iStockphoto/ Thinkstock.
The bar chart shows the amount of food produced from these four ways of farming.
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(a) How much extra food can be produced when farmers grow wheat, compared with keeping sheep outside?
Show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
Answer ........................................ tonnes per hectare per year (2)
(b) Sheep eat grass. For every 1000 g of grass eaten, a sheep increases in mass by only 50 g. The other 950 g is lost.
How is the other 950 g lost?
Tick ( ) two boxes.
As oxygen from photosynthesis
As faeces
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As meat
As carbon dioxide from respiration
(2)
(c) (i) Pigs kept inside lose less energy than pigs kept outside.
Why?
Tick ( ) two boxes.
Pigs kept inside are fed more.
Pigs kept inside are kept in small pens.
Pigs kept inside are kept warm in the winter.
Pigs kept inside are healthier.
(2)
(ii) Meat from pigs kept inside is usually cheaper than meat from pigs kept outside.
Give one reason why.
...............................................................................................................
............................................................................................................... (1)
(Total 7 marks)
Q5.It is important to conserve fish stocks.
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Figure 1 shows a new type of fishing net and a traditional fishing net.
(a) (i) Describe how the new type of fishing net helps to conserve fish stocks.
...................................................................................................................
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...................................................................................................................
................................................................................................................... (3)
(ii) Give one way, other than controlling nets, to reduce overfishing.
...................................................................................................................
................................................................................................................... (1)
(b) Another way to make sure there is food for an increasing human population is to make food production more efficient.
Figure 2 shows how some cows are farmed.
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© Dageldog/iStock
(i) Use information from Figure 2 to suggest two ways in which this type of farming reduces energy loss from the cows.
1 ................................................................................................................
...................................................................................................................
2 ................................................................................................................
................................................................................................................... (2)
(ii) Give two reasons why some people disagree with farming cows in this way.
1 ................................................................................................................
...................................................................................................................
2 ................................................................................................................
................................................................................................................... (2)
(Total 8 marks)
Q6. The drawings below show some of the effects that human activities have on the environment.
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Use information from the drawings to give two ways in which these human activities affect other living organisms.
1 ............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
2 ............................................................................................................................................
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............................................................................................................................................... (Total 2 marks)
Q7. The amount of carbon dioxide in the atmosphere is increasing.
The table shows the estimated mass of carbon dioxide exchanged with the atmosphere in one year.
Mass of carbon dioxide exchanged with the atmosphere in millions of tonnes
Passed out into the atmosphere
Taken in from the atmosphere
Plants 30 64
Animals 10 0
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Microorganisms 24 0
Combustion 6 0
(a) (i) Calculate the total mass of carbon dioxide passed out into the atmosphere in one year.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Answer ............................................ million tonnes (2)
(ii) Calculate the increase in the mass of carbon dioxide in the atmosphere in one year.
You should use your answer to part (a)(i) in your calculation.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Answer ............................................ million tonnes (2)
(b) Draw a ring around the correct answer to complete the sentence.
decomposition.
Plants use carbon dioxide in the process of photosynthesis.
respiration.
(1) (Total 5 marks)
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Q8. The diagram shows part of the human digestive system.
(i) Name part B.
..................................................................................................................................... (1)
(ii) Describe the role of B and D in reducing blood sugar levels.
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..................................................................................................................................... (2)
(Total 3 marks)
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Q9.This question is about hormones.
(a) (i) Hormones carry messages.
What type of messenger is a hormone?
Draw a ring around the correct answer.
chemical electrical environmental
(1)
(ii) Which part of the brain secretes hormones?
Draw a ring around the correct answer.
cerebellum medulla pituitary gland
(1)
(b) Figure 1 shows the level of a pregnancy hormone over a 40-week pregnancy.
This hormone can be detected in a pregnancy test.
Figure 1
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A woman takes a pregnancy test.
In which week of pregnancy is the test most likely to give a positive result?
Use information from Figure 1.
Write the correct answer in the box.
(1)
(c) Figure 2 shows the levels of three other hormones during pregnancy.
The baby is usually born at about 40 weeks.
Figure 2
Adaptation by kind permission of Biozone International
(i) Describe the patterns in the levels of oestrogen and progesterone from 0 to 36 weeks.
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............................................................................................................... (4)
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(ii) Which hormone is likely to stimulate contractions of the uterus (womb) when the baby is born?
Use information from Figure 2 to give a reason for your answer.
...............................................................................................................
...............................................................................................................
...............................................................................................................
............................................................................................................... (2)
(Total 9 marks)
Q10.This question is about the nervous system.
(a) Describe the function of receptors in the skin.
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........................................................................................................................
........................................................................................................................ (2)
(b) A response is caused when information in the nervous system reaches an effector.
(i) There are two different types of effector.
Complete the table to show:
• the two different types of effector
• the response each type of effector makes.
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(4)
(ii) Some effectors help to control body temperature.
Give one reason why it is important to control body temperature.
...............................................................................................................
............................................................................................................... (1)
(Total 7 marks)
Q11.The figure below shows the amount of forest cover on an island in Asia, in 1973 and in 2010.
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(a) (i) Deforestation has decreased the amount of forest cover on the island.
Describe the change in the pattern of forest cover on the island.
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...................................................................................................................
................................................................................................................... (2)
(ii) Give two possible reasons why the amount of forest has decreased between 1973 and 2010.
1 ................................................................................................................
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2 ................................................................................................................
................................................................................................................... (2)
(b) Scientists are concerned about the effects of a decrease in forest cover on ecosystems.
Give two possible negative effects of the decrease in forest cover on ecosystems.
1 ..........................................................................................................................
.............................................................................................................................
2 ..........................................................................................................................
............................................................................................................................. (2)
(Total 6 marks)
Q12.Food chains show the flow of energy through the organisms in a habitat.
(a) The diagram below shows a food chain.
grass sheep human
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The biomass in each stage of the food chain changes as food passes along the food chain.
Draw a pyramid of biomass for this food chain.
Label the pyramid.
(2)
(b) The table below shows three food chains, A, B and C.
Food chain
A plants sheep human
B plants grasshoppers frogs trout human
C plants human
(i) In which food chain, A, B or C, will the greatest proportion of biomass and
energy of the plants be passed to humans? (1)
(ii) Give reasons why the food chain that you chose in part (b)(i) passes on the greatest proportion of biomass and energy to humans.
...............................................................................................................
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............................................................................................................... (3)
(Total 6 marks)
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M1.(a) (i) 2400 cm3
1
(ii) 1400 (cm3)
allow 2 marks for ecf of correct answer to [answer given in (a)(i) – 1000]
allow 1 mark for 2400 – (600 + 400) or equivalent with no or incorrect answer
allow 1 mark for ecf of answer given in (a)(i) – 1000 or equivalent with no or incorrect answer
2
(b) (i) sweat(ing)
allow evaporation
allow perspiration 1
(ii) any one from: • for cooling • to maintain body temperature
1
(c) (i) More water was lost through the skin. 1
(ii) decrease 1
[7]
M2.(a) (i) pancreas 1
(ii) Insulin causes glucose to move into cells. 1
(b) (i) A 1
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rapid rise or fastest 1
(ii) 2 1
(c) The pancreas could be rejected. 1
[6]
M3.(a) A – pituitary 1
B – adrenal 1
(b) ovary 1
(c) diaphragm
allow phonetic spelling 1
(d) condom 1
(e) Level 2 (3–4 marks): A detailed and coherent evaluation is provided which considers a range of advantages and disadvantages and comes to a conclusion consistent with the reasoning.
Level 1 (1–2 marks): An attempt to describe the advantages and disadvantages is made, which may not come to a conclusion. The logic may be inconsistent at times.
0 marks:
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No relevant content.
Indicative content
advantages of the plastic IUD: • is effective for longer than the copper IUD • does not need to be replaced as often as the copper IUD • although the pain of periods are more severe, the pain with the copper IUD is
likely to be worse
• can reduce the bleeding during a period • most of the possible side effects are not serious, eg feeling sick, acne and
headaches.
disadvantages of the plastic IUD: • needs to be implanted for a period of time before it is effective ie not
emergency contraception • can make the pain of period more severe • can cause more side effects than the copper IUD • can cause some more severe side effects such as cysts on the ovaries
an understanding that the side effects are only possible and may not necessarily occur
additional examiner guidance: • pupils should add value to the points in the table and should not just be copies
verbatim • credit can also be given for other correct advantages and disadvantages from
the candidates’ own knowledge and understanding • allow converse points if clearly made
4
[9]
M4. (a) 3 (.0)
correct answer, irrespective of working gains 2 marks.
if the answer is incorrect or there is no answer, award 1 mark for use of correct figures (0.5 and 3.5) [and no other figures]
2
(b) as faeces
if more than two boxes ticked deduct 1 mark for each additional tick
1
as carbon dioxide from respiration 1
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(c) (i) pigs kept inside are kept in small pens
if more than two boxes ticked deduct 1 mark for each additional tick
1
pigs kept inside are kept warm in the winter 1
(ii) any one from:
• faster growth
ignore bigger / less flavour / fatty
• need less food
ignore references to movement / energy
• ready for market sooner
ignore ethical arguments 1
[7]
M5.(a) (i) any three from: • lights to help guide / attract fish (to the holes) • (rigid so) holes stay open • (holes) allow small / young fish to escape • (so that) they can breed
3
(ii) (fishing) quotas / legislation 1
(b) (i) movement is restricted 1
(in a building or close together so) heat is conserved
allow in heated buildings to reduce heat loss 1
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(ii) any two from: • it is cruel
allow descriptions of ‘cruelty’ • disease spreads faster • (meat) often has antibiotics in it
2
[8]
M6. e.g. waste gases/air pollution harms living organisms dumped waste can make land unfit to live on/ drainage pollutes water/harms organisms
for 1 mark each
(if no marks can allow – pollution harms organisms = 1) [2]
M7. (a) (i) 70
award 2 marks for correct answer irrespective of working
allow 1 mark for 30 + 10 + 24 + 6 (with wrong answer or no answer), do not award this sum if other figure(s) are included in the addition
2
(ii) 6
award 2 marks for correct answer irrespective of working
award 2 marks for correct answer to (a)(i) – 64 (ecf)
award 1 mark either for 70 – 64 or answer to (a)(i) – 64 with no answer or incorrect answer
2
(b) photosynthesis. 1
[5]
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M8. (i) liver 1
(ii) liver or B stores glycogen or pancreas or D makes insulin
1
clear description of link 1
[3]
M9.(a) (i) chemical 1
(ii) pituitary gland 1
(b) 8
allow 9 or 10 1
(c) (i) any four from: • progesterone starts being produced at 4 weeks / no progesterone
before 4 weeks • and then / from 4 weeks increases • oestrogen at constant / low level (from 0) to 20 weeks • and then / from 20 weeks increases • from 20 − 36 weeks level of O rises more steeply than that of P or • P is always higher than 0 from 6 to 36 weeks
if no other marks awarded, allow progesterone and oestrogen both increase / rise for 1 mark.
4
(ii) oxytocin 1
level of oxytocin increases just before birth 1
[9]
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M10.(a) detect changes in surroundings or detect stimuli
allow any named stimulus for skin 1
convert information to impulse
allow send impulse to sensory neurones / brain 1
(b) (i)
muscle contract(ion)
gland release / secrete / produce chemical / hormone / enzyme
1 mark for each effector
1 mark for each response
response must match type of effector (if given)
ignore examples
ignore relax(ation) / movement for contraction
do not allow expansion for muscles 4
(ii) any one from:
• (maintain temperature at which) enzymes work best • so chemical reactions are fast(est) • prevent damage to cells / enzymes
allow prevent enzymes being denatured (by temperature being too high)
1
[7]
M11.(a) (i) forest at the edges (of the island) has been removed
allow centrally the forest remains 1
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an appropriate area on the island is identified eg south east or bottom right 1
(ii) any two from: • (to provide land) for farming / agriculture • (to provide land) for quarrying • (to provide land / wood) for building
allow to provide timber • to provide fuel • to produce paper
allow forest fires 2
(b) any two from: • decreased biodiversity • loss of habitats • increased carbon dioxide (concentration) • global warming
allow effects of global warming eg flooding / rise in sea level
allow soil erosion 2
[6]
M12.(a) 3-layered triangular pyramid
as blocks or layered triangle, ignore (small) gaps between layers
1
(pyramid) labelled in food chain order
all three labels are required
for 2 marks the pyramid must be fully correct 1
(b) (i) C 1
(ii) shortest or fewest stages / transfers / (trophic) levels
allow only if (b)(i) is C or blank 1
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less losses in waste / faeces / urine / CO2 / excretion
allow smaller amount uneaten 1
less loss in respiration / heat / movement
allow less lost keeping warm
do not allow energy for respiration
do not allow respiration makes energy
allow less loss (of biomass / energy) or less transfer (of biomass / energy) to surroundings if neither 2nd nor 3rd point given, for 1 mark
1
[6]
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E1.(a) (i) Most students were able to calculate the 2400 cm3 water loss from the body.
(ii) Only a small number of students who had made an error in their calculation gained the mark for their working. Most students who arrived at the incorrect answer showed no working, making it impossible to award any credit. Some, who had selected 1800 cm3 in part (a)(i), went on and used it here and gained two marks for using that figure to calculate the volume needed to be drunk correctly, based on this incorrect value. The students who gained no marks often used 1000 in an addition or division or simply gave ‘1000’ as their answer.
(b) (i) Most students gave the correct response and stated that the process by which water was lost from the skin was ‘sweating’. ‘Perspiration’ and ‘evaporation’ were also given credit. Incorrect responses were usually ‘respiration’, possibly confused with ‘perspiration’ or ‘urine’ possibly due to incomplete reading of the question.
(ii) Many correct ideas about ‘cooling’, or ‘maintaining body temperature’ were seen. However common misconceptions were thinking that sweating was involved in ‘balancing the body’s water content’, allowing ‘space for more water’, ‘moistening’ or ‘hydrating’ the skin, ‘losing weight’ or ‘getting rid of bacteria’.
(c) (i) It was well understood that increasing temperature would mean that more water would be lost through the skin.
(ii) There was considerable confusion as to whether the increase in temperature would increase, decrease or indeed have no effect on the volume of urine lost. As a result, fewer than half the students gained this mark.
E2.(a) (i) The vast majority of students could correctly identify which organ monitors blood glucose level. The most common incorrect answer was for choosing the liver as the blood glucose monitoring organ.
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(ii) Only approximately one quarter of students could identify what effect insulin has on the glucose in the blood. The two incorrect answers were both seen in significant numbers but the most common was for the idea that insulin converts glucose to starch.
(b) (i) and (ii) A third of all students gained full or partial credit for identifying the correct type of insulin to inject given the context of the question and for then giving a reason for this. The context of the question was a meal high in carbohydrates and therefore the appropriate choice was A, as this is the fastest acting. Most students that did not gain marks identified C as the insulin of choice and explained that it lasts the longest.
Of those students that only gained one mark, they generally chose the correct type of insulin but went on to say that it gave the ‘highest’ amount of insulin. Whilst this is true, it is not the important consideration when choosing the type of insulin to use in this context, it needed to be the fastest acting.
(c) This question was well answered, with most students correctly identifying a possible disadvantage of a pancreas transplant.
E4. (a) Most students selected the correct figures, ‘3.5’ and ‘0.5’, and then went on to complete the calculation correctly, in part (a). Both marks were awarded irrespective of working, if a candidate gave the correct answer, ‘3’. Some students, though, chose the correct figures and then used them incorrectly, for example adding, multiplying or dividing one by another. Provided these students showed their calculations they were awarded one mark for use of the correct figures. A number of students though arrived at an incorrect figure without showing working. Hence a candidate who gave the answer ‘4’ may well have added 3.5 and 0.5 but as they did not show their figures, no mark was awarded. The attention of students should be drawn to the advice on the front page ‘In all calculations, show clearly how you work out your answer’.
(b) Some students did not read the instructions carefully and ticked only one box, thus reducing their potential marks. Approximately two-thirds of the students scored both marks.
(c) (i) Again some students did not read the instructions carefully and ticked only one box. More than half of the students scored both marks.
(ii) This part was a development of the theme in (c)(i). Having identified that pigs kept inside lose less energy than those kept outside, students were asked to explain why meat from pigs kept indoors is usually cheaper. Better students
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realised that this is because these pigs grow faster and gained the mark, however far too many students went off at a tangent and offered all manner of unacceptable suggestions, such as pigs kept indoors would be ‘bigger’, have ‘less tasty meat’ or even have ‘dirty meat’. Other students referred to the ethics of keeping pigs indoors and often suggested that ‘free-range pigs would have more expensive meat’, which missed the point, somewhat. Students who referred to less movement usually did not go on to develop the idea that this would result in faster growth.
E5.(a) (i) Two thirds of all students gained partial credit in this question, but only a very small percentage gained full credit. Most students recognised that the large holes allowed smaller fish to escape and some students gained a second mark for explaining that these smaller fish go on to breed. A minority of students recognised that the lights attracted the fish to holes to help them escape. Many students, if referring to the lights, thought they attracted fish into the net or that they let the fisherman see how many fish had been caught in the dark. Very few students identified that the rigid plastic kept the holes open.
(ii) Most students knew that there needed to be reduced fishing or that certain areas needed to be avoided when fishing, but many didn’t clearly portray the idea of these reductions being enforced, against the law or ‘not allowed’. Most marks that were awarded had mentioned ‘quotas’.
(b) (i) The vast majority of students realised that movement of the cows was restricted and gained the mark, but this was sometimes described quite poorly and some answers merely stated that the cows were squashed in, which was insufficient for the mark. Some students achieved marking point 2 by giving a really good explanation of conserving heat but many students explained that the cows would eat all day as the food was in front of them but this was not credit worthy for the question asked.
(ii) Many students could give a reason why some people disagree with farming cows in an intensive way and a small proportion could give two credit worthy responses. Most students gained a mark for recognising that the practice is seen as cruel and they described this in a variety of ways. Stating that this was unethical was insufficient on its own. A smaller proportion identified the spread of disease as a possible reason but the idea that the meat would have
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antibiotics in it was very rarely seen.
E6. All that was required was the effects of pollutants on living organisms. Most answers were at the level of ‘smoke pollutes the air’ or ‘oil damages the sea’.
E7. (a) (i) Many candidates secured both marks, and most of these followed the instructions to show their working. Of those who arrived at the wrong answer, one mark was available for showing the correct calculation (without additional numbers). It is perhaps surprising that a considerable number of candidates appeared not to have calculators with them, as the tortuous process of adding each number in turn was evident in a number of papers. Furthermore, when calculators are used it is always advisable that candidates should consider whether their answer is correct, as it is all too easy, in the pressured situation of the examination, to press the wrong key. At least double checking the answer, preferably via a different route, should be a minimum.
(b) Most candidates knew that carbon dioxide is used in photosynthesis, although some will have inevitably continued their incorrect train of thought from question (b), as ‘respiration’ proved to be the most attractive distractor here.
A significant minority of candidates failed to make any effort here perhaps believing that they were required to conjure the figure required to be deducted from their answer to (a)(i), from memory. Again, for those who knew how to carry out the calculation but could not complete it correctly, one mark was awarded if the calculation was shown. Fewer candidates were awarded the single mark here, than in (a)(i). The most common error was to add 64 to the answer given in part (i), rather than to subtract it, thus a common incorrect response was ‘134’. Had these candidates stopped to consider this answer they might have wondered how the annual increase in carbon dioxide in the atmosphere could be greater than the total of all the inputs. Again, the number of candidates who were unable to subtract (or add, if they were doing the wrong sum) correctly surprised examiners.
E8. Although many candidates knew that insulin is produced by the pancreas, surprisingly few were able to describe the effect it has on the liver to achieve a reduction in blood sugar levels.
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E9.(a) Nearly all students knew that the hormones are chemical messages.
(b) Most of the students knew that the pituitary gland secreted hormones.
(c) (i) The question assessed students’ AO2 skill in data interpretation in the context of oestrogen and progesterone levels during pregnancy. Two thirds of students scored maximum marks. Most students were able to describe the patterns in the level of the hormones with emphasis on oestrogen staying the same for 0-20 weeks and then rising steadily. However, some students lost the first mark because they were not clear on progesterone being produced from 4 weeks, or that there were no progesterone in the first 4 weeks before it starts to rise. Very few students included the last marking point in their answer.
(ii) Most of the students answered the question correctly that oxytocin level increases just before birth or rises sharply towards the end of pregnancy. However, a few students referred to oestrogen or progesterone patterns rather than oxytocin, and hence lost all the marks.
E10.(a) This question asked about receptors in the skin, rather than receptors in general. Thus students who qualified the first point with inappropriate stimuli, such as ‘light’ or ‘sound’, were not credited with the mark. Furthermore it should be noted that the skin does not detect ‘temperature’, but rather ‘changes in temperature’, although in a list of otherwise correct stimuli, this inaccuracy was ignored. Anthropomorphic answers had the receptors ‘feeling’, ‘thinking’ and ‘deciding’ whilst others suggested that the receptors were themselves effectors in bringing about the response. In terms of the second marking point, although many described the role of receptors in sending ‘impulses’ or the barely acceptable ‘signals’, many others reverted to the inadequate ‘messages’, additionally these impulses were often sent directly ‘to muscles’, rather than ‘the brain / spinal cord’ or ‘via sensory neurones’.
(b) (i) Many students had learned this part of the specification well and the format of the question allowed them to gain four marks in a fairly straightforward way. The question identified that ‘there are two types of effector’, thus answers that identified a specific muscle or gland were not awarded the marks in the first column. Many thought that hormones or specific examples of hormones were effectors and that glands were responses. There were many instances of ‘neurone’, ‘synapse’ or ‘spinal cord’ in the effector column with equally wrong matching words in the response column. The response column often contained examples of simple reflex actions. The mark scheme was applied strictly: thus specific examples of effectors were ignored unless preceded by the correct general term. The ‘relaxation’ of muscles was ignored, whilst
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‘expansion’ of muscles negated any other words written in that part of the table. Many students were unable to offer any suggestions whatsoever and left the table blank. Perhaps a little more attention to the mark allocation here might have prompted some of these to at least have a go at answers, rather than give up so many marks without effort.
(ii) A significant proportion of students could offer no more than the need to avoid body temperature becoming too high or too low, thus doing little more than restating the question. Better answers, perhaps from students who had studied other units, referred to the possible ‘denaturation of enzymes’, although a considerable number of these lost the mark by describing denaturation as a result of ‘low temperatures’, whilst others appeared to believe that enzymes work at only one specific temperature.
E11.(a) (i) Most students gained full or partial credit, with the majority of students scoring one mark. Marking point 2 was awarded most frequently for giving a specific area of the island which had been affected. Far less students achieved marking point 1 for recognising the general pattern of deforestation around the edges / coasts, and only a small percentage of students gave the alternative marking point of the ‘central areas remain unchanged’.
Where students did not gain credit it was often because they simply stated ‘it has been deforested’ without giving further details on which areas of the island have been affected. This was information given in the stem of the question. Some extremely good answers had actually included data which had been manipulated from the map such as estimating the percentage of forest lost or the area of forest lost.
(ii) Most students could give two possible reasons why the forest cover had decreased. Marking point 1 relating to farming or specific examples such as cattle ranching and marking point 3 relating to building / timber or specific examples of building, such as for houses, were seen in the majority of answers. Marking point 2 relating to quarrying was very rarely seen as was the additional point for forest fires. Where students failed to score two marks it was generally because of non-specific examples being given such as ‘for wood’, ‘for materials’, ‘for resources’, ‘for economic reasons’ or ‘for space’. The minority of students who scored zero in this question showed no understanding of reasons for deforestation by giving reasons such as ‘diseases killed trees’ or ‘no nutrients in the soil’.
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(b) Most students could give two possible negative effects of the decrease in forest cover on ecosystems. Marking points 1 and 2 were seen in the vast majority of answers with extinctions frequently being given as an alternative to reduced biodiversity. Marking points 3 and 4 were seen far less often, with marking point 4 occasionally being awarded for examples of global warming.
Incorrect answers often related to the impact deforestation would have on food chains or how prey will no longer have any cover and so will be hunted easier, without developing this idea to include reduced habitats and biodiversity. Other incorrect answers seen included more methane due to cattle ranches being opened or a reduction in oxygen in the atmosphere as there are less trees photosynthesising.
E12.(a) The majority of students were able to draw the three layered pyramid with the three labels in correct food chain order. Drawings were not accepted as an alternative to word labels. Three blocks or triangular shapes with three layers were equally acceptable and the orientation of the pyramid was ignored. Some students lost one mark for labelling the layers incorrectly, usually with grass showing the smallest biomass and humans the largest. Students who did not score marks on this question frequently put the organisms at the vertices of a triangle or just redrew the food chain given in the question. A small but significant minority made no attempt at this question.
(b) (i) The instruction to choose one from A, B or C, proved difficult for some students. Although the majority chose the correct answer, ‘C’, many of the remainder chose ‘B’ as the correct food chain. However, the response from large numbers of students was not any of these letters, ‘P’, ‘R’, ‘J’, ‘frogs’, and an array of numbers were provided, none of which gained a mark
(ii) Choosing the incorrect food chain in part (i) meant that it was difficult to score marks here, although some did manage to do this. Many students did understand that the ’shortest food chain’, expressed in a variety of ways, would allow the least energy or biomass loss. ‘Passed directly to humans’ was a common way of indicating that this was the shortest food chain. A common misconception was that longer food chains meant that organisms would gain more biomass for the humans. Another error seen was to think that sheep were larger or had more protein and so would provide more biomass. Often two examples of energy losses were in the same marking point group and so only one mark could be awarded e.g. ‘less loss in faeces’ and ‘in urine’ was only worth one mark as the question had asked about both biomass and energy.
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