1.

Choose words from this list to complete the sentences below. decomposition fermentation microbes plants purification sewage

Waste from human bodies is treated at a ...................................................... works. It is broken down into simpler substances by ........................................................... This process is called .................................................................................................(Total 3 marks)

2.

Describe what happens to chromosomes when a normal body cell divides. ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 2 marks)

3.

(a)

A gardener was told to let more air into his heap of garden waste.

Explain why this would help decay. ..................................................................................................................................... .....................................................................................................................................(1)

(b)

Write down two further conditions which speed up the decay of garden waste in a compost heap. 1. 2. .......................................................................................................................... ..........................................................................................................................(2) (Total 3 marks)

1

4.

Cystic fibrosis is a disease which affects 1 in 1600 babies. (a) What are the symptoms of cystic fibrosis? .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................(3)

(b)

Two parents with normal characteristics have a child who was born with cystic fibrosis. Explain, as fully as you can, how this can happen. You may use a genetic diagram if you wish. .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................

(4) (Total 7 marks)

2

5.

The figures below show how the yield of a wheat crop is affected by adding nitrogen fertiliser.

N itr o g e n fe r tilis e r a d d e d (k g /h e c ta r e ) 50 75 100 125 150 175 200 0

Y ie ld (to n n e s/h e c ta r e ) 2 2 3 3 4 4 4 4 6 8 1 4 0 3 4 4

(a)

Display these results on the graph paper in the most suitable way.

(4)

3

(b)

What conclusions can you draw from the graph? ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 7 marks)

6.

Cows convert some of the food they eat into milk. Bovine somatrophin (BST) is a chemical used in the dairy industry. The figures show the food intake for a cow and its milk yield per day before and after treatment with BST.

B e fo re B S T tre a tm e n t T o ta l fo o d e a te n

35 kg

28 kg m ilk

A fte r B S T tre a tm e n t T o ta l fo o d e a te n

40 kg

35 kg m ilk

(a)

What is the effect of BST on the performance of the cow? ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

4

(b)

What factors should the farmer consider before using BST? ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(4) (Total 6 marks)

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7.

On a hot day, a student has an iced drink. Graphs I and II show some of the changes to the students body produced by the iced drink. I Tem p (C ) 3 7 .7 3 7 .5 3 7 .3 3 7 .1 3 6 .9 3 6 .7 0 10 20 Ic e d r in k ta k e n 30 40 50 60 T im e (m in u te s ) S k in te m p e ra tu re B ra in te m p e ra tu re

II

R a te o f e v a p o ra tio n o f s w e a t fro m s k in R a te o f b lo o d flo w to sk in

R a te (a rb ita ry u n its)

0

10

20 Ic e d r in k ta k e n

30

40

50

60 T im e (m in u te s )

6

Use the information from the graphs to explain, as fully as you can, why the temperature of the students skin rises after she has taken the iced drink. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 4 marks)

8.

The graph shows how the rate of photosynthesis is affected by different conditions. 4% C O2

a t 2 5 C

R a te o f p h o to s y n th e s is

4% C O

2

a t 1 5 C

0 .0 3 % C O 0 .0 3 % C O L i g h t i n t e n s i t y

2 2

a t 2 5 C a t 1 5 C

(a)

What patterns can you find from this graph? ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(5)

7

(b)

How useful could this information be to a grower using glasshouses? Give reasons for your answer. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2) (Total 7 marks)

9.

Mushrooms can be grown on compost. The compost is made by mixing straw and manure which rot down.

(a)

Write down three things which are needed for the straw and manure to rot. 1. 2. 3. ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(3)

(b)

Some substances, like plastic, are not biodegradable. What does this mean? ..................................................................................................................................... .....................................................................................................................................(1) (Total 4 marks)

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10.

In some developing countries woodland is cut down and burned. The ash acts as fertiliser. Crops are grown for three years. The land is then left as it is too poor to grow any more crops.

woodland

grass

cleared land where crops were grown

wood

(a)

In the original woodland trees and plants died and grew for hundreds of years. When cleared the land grew crops for only three years. Explain this difference in as much detail as you can. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3)

(b)

What could farmers do to make crops grow on the cleared land for more than three years? ..................................................................................................................................... .....................................................................................................................................(2) (Total 5 marks)

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11. P A N Ch

R

T o o m u c h g l u c o s e i n b l o o d n o r m a l b l o o d s u g a r l e v e l n g

o r m og nl u e c i n s u l i n

E

A

S

L I V o i ns es o

E R l u b

l e

g

l y

c o

g

e n

n b

o r m a l l o o d s u l e v e l

g

a r

o t e n o u g h l u c o s e i n b P A N C R E

h o r m o n e g l u c a g o n

l o

o

d

A

S

g

l y

L I V E R c o g g e l nu c o

s e

The diagram shows how the blood sugar level is controlled in the body. Explain fully what would happen if somebody ate some glucose tablets. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 4 marks)

12.

Huntingtons chorea is a disease found in 5 out of every 100 000 people. (a) Describe, as fully as you can, how the disease is likely to affect these people. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3)

10

(b)

Some members of the Smith family suffer from Huntingtons chorea. The family tree gives details.

M a r y 's m o t h e r (N O R M A L )

M a r y 's f a t h e r (N O R M A L ) M a ry Jo n e s (N O R M A L )

J o h n 's m o th e r (N O R M A L ) J o h n S m ith ( H U N T I N G T O N 'S C H O R EA ) C h ild r e n ?

J o h n 's f a t h e r ( H U N T I N G T O N 'S C H O R EA )

(i)

Are Mary and John Smiths children likely to have Huntingtons chorea? Explain your answer as fully as you can. Use a diagram if it will help. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(4)

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(ii)

Suppose Mary and John both carry one gene for Huntingtons chorea. How likely are their children to have Huntingtons chorea? Explain your answer as fully as you can. Use a diagram if it will help. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................

(2) (Total 9 marks)

13.

Plants produce glucose by a process called photosynthesis. carbon dioxide + water light chlorophyll oxygen + glucose

The plant uses glucose to grow.

12

(a)

The graph shows the change in concentration of carbon dioxide in a glasshouse full of plants over 24 hours.

in c re a s in g c o n c e n tra tio n of gas

0 m id n ig h t

6 daw n

12 m id d a y

18 dusk

24 m id n ig h t

Draw a line on the graph to show how the concentration of oxygen changes in the glasshouse.(3)

13

(b) white green

Some plants have variegated leaves with white parts which contain no chlorophyll. How do you think a variegated geranium would grow compared to a similar sized geranium with all green leaves? Explain your answer.................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2) (Total 5 marks)

14.

(a)

1m of a field gets about 1050MJ of light energy per year.

Only 21 500kJ of energy is stored in the new grass. (i) How is the energy stored in the new grass? ...........................................................................................................................(1)

(ii)

What is the % of light energy stored in the grass? ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(1)

14

(b) 1020 kJ for energy

125 kJ new growth 3050 kJ eaten 1905 kJ in faeces

The diagram shows what happens to the energy from grass in part of a field which is grazed by a bullock. Using information in the diagram suggest why food chains are usually short. ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ...................................................................................................................................(3)

(c)

Many of the animals which from part of our diet are herbivores rather than carnivores. Explain why as fully as you can. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 8 marks)

15.15

A farmer had too much manure to spread on his fields. He thought he would turn it into compost which had no smell.

(a)

What makes the manure decay? .....................................................................................................................................(1)

(b)

Write down two conditions which will help the manure to decay faster. 1. 2. ........................................................................................................................... ...........................................................................................................................(2) (Total 3 marks)

16.

Plants are grown in glasshouses to protect them from the weather or extend the growing season. Plants make food by photosynthesis.

energy from 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2 light glucoseIn winter, when days are shorter, glasshouses are heated to keep the enzyme reactions in plants at optimum rates.

16

What else should a grower do to make sure that the plants are photosynthesising at the optimum rate? Give a reason for your answer. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 3 marks)

17.

Cepaea nemoralis is a snail which is found on sand dunes. It may have a plain or banded shell. The snails are found on grass stalks and leaves.

Plain

Banded

A scientist collected young unbanded snails and kept them until they were fully grown and mated them. The eggs laid produced 35 unbanded and 12 banded snails.

17

(a)

Explain these figures as fully as you can. You may use a genetic diagram if you wish to make your answer clearer. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(7)

18

Variation in colour (b)

Variation in banding

The snail shells show a lot of variation in colour. They are yellowy/green, brown, pink or cream. The banding varies from a single wide band to a mixture of thick and thin bands. Describe briefly the factors which have produced this variation and explain how these factors may themselves have arisen. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(4) (Total 11 marks)

19

18.

Food decays more slowly if it is kept dry or cool.

Explain why. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 3 marks)

19.

The family trees below show the inheritance of hair colour in two families. P e o p le w ith b la c k h a ir a re s h o w n a s : P e o p le w ith re d h a ir a re s h o w n a s :

B ill S m a rt

A n n S m a rt

Tom Jones

Jo y Jo n es

Jo h n S m a rt

M a ry Jo n e s

20

(a)

The allele for black hair is dominant over the allele for red hair. Use the letter B as the allele for black hair. Use the letter b as the allele for red hair. Complete the diagram below to show the chances of Mary Jones inheriting red hair.

Tom Jones h a ir c o lo u r b la c k

Joy Jones b la c k

a lle le s in p a re n ts

a lle le s in sp e rm s a n d e g g s

a lle le s in c h ild r e n

h a ir c o lo u r

re d (M a ry Jo n e s)(4)

21

(b)

John Smart and Mary Jones grew up, got married and had a child. What would the chances be that the child had red hair? ....................................................................................................................................(1)

Explain your answer. Use a genetic diagram if it makes your answer clearer. .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................

(3) (Total 8 marks)

20.

The diagram shows three types of cells in a life history of a simple animal.

22

(a)

How do the chromosomes of the body cells compare with the chromosomes in the fertilised egg from which they came? .................................................................................................................................... ....................................................................................................................................(1)

(b)

Describe what happens to chromosomes in the nucleus of a body cell when it forms reproductive cells. .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................(4) (Total 5 marks)

23

21.

Spiders produce a protein thread which is extremely strong compared to man-made fibres of the same diameter.

Explain how genes control the way the protein is made in the spiders body. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 4 marks)

22.

The table below shows a wheat farmers calendar. O c to b e r M a rc h A p ril M ay W in te r W h e a t is s o w n a n d g e rm in a te s . P h o s p h a te /p o ta s h f e r tilis e r is a p p lie d . W h e a t p la n ts re s u m e g ro w th . N itr a te f e r tilis e r is a p p lie d . A m m o n iu m n itr a te , th e m a in f e r tilis e r, is a p p lie d . F u n g ic id e m a y b e s p r a y e d to c o n tr o l m ild e w o r r u s ts o n w h e a t. E x tr a a m m o n iu m n itr a te f e r tilis e r m a y b e a p p lie d . A s e c o n d s p r a y in g o f f u n g ic id e m a y b e n e e d e d . D w a rfin g h o r m o n e s p ra y e d to k e e p w h e a t s tra w (s ta lk s ) s h o r t. In se c tic id e sp ra y a g a in st a p h id s m a y b e n e e d e d . E x tr a s p r a y in g o f f u n g ic id e m a y b e n e e d e d . W h e a t is h a rv e s te d . G r o u n d s p r a y e d w ith w e e d k ille r. S tu b b le (re m a in s o f w h e a t p la n ts ) is p lo u g h e d in re a d y fo r th e n e x t c ro p .

Ju n e

A u gu st A u g u s t/ S e p te m b e r

24

This process uses expensive fertilisers and pesticides to grow pest free crops which may be produced in excess. What are the reasons for and against growing wheat in this way? For ........................................................................................................................................ ............................................................................................................................................... ...............................................................................................................................................(3)

Against ................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................(4) (Total 7 marks)

23.

Choose words from this list to complete the sentences below. carbon dioxide cool insects dry microbes moist nitrogen warm oxygen

Food decays because it is broken down by ............................................................ Food decays faster in conditions which are ........................... and ......................... It will also decay faster if the air around it contains plenty of gas.(Total 4 marks)

24.

Scientists have found the following food web in the Antarctic Ocean. p e n g u in tin y g r e e n p la n ts ( p h y to p la n k to n ) s h r im p cod s q u id seal

25

(a)

(i)

Write down the name of the producer in this web.

........................................................................................................................... (ii) Write down the names of two organisms which are prey in this web. ........................................................................................................................... ...........................................................................................................................(3)

(b)

Humans are removing large numbers of the cod. Some scientists argue that this could lead to a decrease in the numbers of squid and penguins. Others argue that the numbers of squid and penguins will stay the same. Carefully explain each argument. Why they might decrease. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................

Why they might stay the same. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

26

(c)

The following information is about the biomass of the organisms in one of the food chains in the web.tin y g re e n p la n ts 1 0 0 0 to n n e s s h rim p 1 0 0 to n n e s cod 1 0 to n n e s seal 0 .5 to n n e

Draw and label a pyramid of biomass for this chain.

(2) (Total 7 marks)

25.

The diagram shows part of the carbon cycle. c a r b o n d io x id e in th e a ir p ro c e ss A

fo x

grass (c o n ta in s c a r b o h y d r a te s , fa ts a n d p r o te in s )

ra b b it

(a)

Write down the name given to process A. .....................................................................................................................................(1)

27

(b)

Explain, as fully as you can, how some of the carbon in the grass becomes part of the foxs body. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 4 marks)

26.

For many years scientists studied the organisms in an area of grassland. One of the animals was a species of black fly. In this population only one allele B existed for colour. All the flies were homozygous BB. A mutation occurred which produced a new recessive allele b which could produce a green colour.

(a)

Draw two genetic diagrams to show how the single b allele in just one fly was able to produce homozygous bb green flies in two generations. First generation

Second generation

(4)

(b)

Although this new allele was recessive and the mutation only occurred once, a large proportion of the fly population was soon green.28

Suggest in terms of natural selection why the recessive b allele was able to spread through the population. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 7 marks)

27.

Scientists have found the following food web in the cold Antarctic Ocean. p e n g u in tin y g r e e n p la n ts (p h y to p la n k to n ) s h r im p cod s q u id seal

(a)

Humans are removing large numbers of the cod. Some scientists argue that this could lead to a decrease in the numbers of squid and penguins. Others argue that the numbers of squid and penguins will stay the same. Carefully explain each argument. Why they might decrease. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(1)

29

Why they might stay the same. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

(b)

The following information is about the biomass of the organisms in one of the food chains in the web.tin y g re e n p la n ts 1 0 0 0 to n n e s s h rim p 1 0 0 to n n e s cod 1 0 to n n e s seal 0 .5 to n n e

Draw and label a pyramid of biomass for this chain.

(2)

(c)

Explain, as fully as you can, why the conversion of shrimp biomass into cod biomass is more efficient than that of cod biomass into seal biomass in the cold Antarctic Ocean. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3)

30

(d)

Boats from many countries fish the Antarctic Ocean. The cod are being overfished. If the numbers of cod are to increase, the population must be carefully managed. (i) Suggest two control measures which would prevent a further drop in numbers, ........................................................................................................................... ...........................................................................................................................(2)

(ii)

Suggest why one of your control measures would be difficult to put into practice. ........................................................................................................................... ...........................................................................................................................(1) (Total 11 marks)

28.

The bean aphid is a type of black-fly which lives on broad bean plants in summer. In the autumn, males and females mate and produce eggs.

(a)

Name the type of reproduction which produces the eggs. .....................................................................................................................................(1)

(b)

In spring these eggs hatch. The young aphids are all female. Explain why they are all similar but not identical to each other. .....................................................................................................................................(1)

31

(c)

These females are then able to produce offspring without needing any males. (i) Name the type of reproduction where females do not need males to produce offspring. ...........................................................................................................................(1)

(ii)

How will the offspring from one of these females: A compare with each other ........................................................................................................................... B compare with the offspring from other females? ...........................................................................................................................(2)

(d)

Some scientists investigated mutations in these aphids. They exposed the aphids to X-rays. They plotted their results. 20

15 P e rc e n ta g e of m u ta tio n s 10

5

In c re a s in g d o s e o f ra d ia tio n

32

(i)

What was the connection between the dose of X-rays and the percentage of mutations? ...........................................................................................................................(1)

(ii)

Name one other possible cause of mutations. ...........................................................................................................................(1) (Total 7 marks)

29.

In compost heaps, dead plants are broken down by microbes. This breakdown is much slower: when the weather is cold when the weather is dry when the heap is squashed down so that no air can circulate.

(a)

What three conditions inside compost heaps are needed for microbes to work quickly? 1 .................................................................................................................................. 2 .................................................................................................................................. 3 ..................................................................................................................................(3)

(b)

Why is the breakdown of dead plants important for living plants? ..................................................................................................................................... .....................................................................................................................................(1) (Total 4 marks)

33

30.

Copepods are tiny animals which live in the sea.

During the day they live deep down near the sea bed. At night they move up to the surface where they feed on tiny plants. When the sun rises they move down to the bottom again.

(a)

Suggest why the tiny plants live near the surface of the sea. ..................................................................................................................................... .....................................................................................................................................(2)

(b)

Herring feed on copepods. Where will herring be found during the day? Give a reason for your answer. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2) (Total 4 marks)

34

31.

Cystic fibrosis is an inherited disease which causes the tubes in the lungs to be blocked with sticky mucus. Two parents who do not have the disease can still produce children who do have the disease. (a) Explain how children can inherit this disease from parents who do not have it (use a genetic diagram in your answer if you want to). ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(4)

(b)

Mucus contains protein. The information for the production of this protein is stored in a gene. Explain how a change in a gene causes a different protein to be produced. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 7 marks)

35

32.

To produce cheap meat, animals must be grown (reared) efficiently. When pigs are reared intensively they are kept indoors. Their surroundings are closely monitored to make sure they have even ventilation and the correct temperature. The risk of infection is high but is reduced by feeding them antibiotics and removing their faeces. The pigs live in cages and cannot move around much.

(a)

Explain why farmers control the temperature. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

(b)

Explain why farmers want to stop the pigs moving about. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

(c)

Give two arguments against rearing pigs indoors instead of rearing them outdoors. 1 .................................................................................................................................. 2 ..................................................................................................................................(2)

36

(d)

Sometimes sewage escapes from pig farms into nearby streams and rivers. This causes a large increase in the amount of nitrates in the water. Use your understanding of the nitrogen cycle to explain how nitrates are produced from the sewage. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(4) (Total 10 marks)

33.

(a)

In sexual reproduction a sperm cell joins with an egg cell.

Complete the sentences by choosing the correct words from the box. bladder (i) (ii) kidney liver lung ovary testis

The organ in which a sperm cell is made is the ............................................(1)

The organ in which an egg cell is made is the ...............................................(1)

(b)

What name is given to the process in which sperm cells and eggs cells join together? ....................................................................................................................................(1)

37

(c)

Two new cells are formed from one cell by asexual reproduction.

O rig in a l c e ll A

N e w c e ll B

and

N e w c e ll C

How, genetically, does the nucleus of new cell C compare with: (i) the nucleus of the other new cell B; ...........................................................................................................................(1)

(ii)

the nucleus of the original cell A? ...........................................................................................................................(1) (Total 5 marks)

34.

(a)

This student is examining plant cells.

38

This shows the students labelled diagram of one of the plant cells. V a c u o le C y to p la s m N u c le u s C e ll m e m b ra n e C e ll w a ll

C h lo ro p la s ts

Complete each, of the following sentences. (i) (ii) (iii) The cell wall is made of ..................................................................... . The function of the cell wall is to ........................................... the cell. Chloroplasts contain ........................................... which is needed for ...................................... . (iv) The vacuole contains ....................................... which is mostly water.(5)

(b)

This student is investigating enzymes.

(i)

What is the temperature of the water in the beaker? ................................... C(1)

39

(ii)

What does an enzyme do? ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(2)

(iii)

Enzymes have many uses. For example they are used in some washing powders. Give two examples of other uses for which enzymes, or products containing enzymes, are sold. 1. ..................................................................................................................... 2. ....................................................................................................................(2)

(c)

An enzyme is used in a chemical reaction. The graph shows the speed of the reaction at different temperatures. F ast

Speed of re a c tio n

S lo w 37 C (i) Complete the following sentence in your own words. At 37 C the reaction ........................................................................................ ...........................................................................................................................(1)

T e m p e ra tu re

40

(ii)

What makes you think that this enzyme could work well in the human body.? ........................................................................................................................... ...........................................................................................................................(1) (Total 12 marks)

35.

The diagram shows part of the carbon cycle. C A R B O N D IO X ID E in th e A T M O S P H E R E

P ro c e ss B

P ro c e ss C

P ro cess A

C H A L K and L IM E S T O N E

O IL a n d N ATU RA L G A S

CA R B O N C O M PO U N D S in P L A N T S

C A RB O N CO M PO U N D S in A N I M A L S

P ro c e ss D

What are the processes shown as A, B, C and D? (i) (ii) (iii) (iv) Process A is ................................................................................................................ Process B is ................................................................................................................ Process C is ................................................................................................................ Process D is ................................................................................................................(Total 4 marks)

41

36.

(i) What is the name of the process which takes place in living cells in your body and which releases energy from oxygen and glucose? .....................................................................................................................................(1)

(ii)

Name the two products of the process in part (i). ............................................................... and ..............................................................(1) (Total 2 marks)

37.

(a) Starch and protein are foods which have to be digested before they can be absorbed. For each, state the enzyme involved in the digestion process, where it occurs in the digestive system and what is formed and absorbed. Food Starch Enzyme ............... Where digestion occurs ...................................... ...................................... What is formed and absorbed .................................................. ..................................................(4)

Protein ...............

The diagram shows part of the lining of the small intestine. Digestion involves the breakdown of large molecules to smaller ones which are absorbed into the blood stream through the microvilli of the epithelial cells.

M ic ro v illi E p ith e lia l c e ll P a rt o f a v illu s lin in g th e s m a ll in te s tin e C a p illa r y

42

(b)

Why are epithelial cells, which form the lining of the small intestine, adapted to be the shape shown? .................................................................................................................................... ....................................................................................................................................(1) (Total 5 marks)

38.

(a) (i) Complete the genetic diagram to show the possible combinations of gametes for the four children and state the sex of the child for each combination. P a re n ts X X X Y

P o s s ib le c o m b in a tio n s Sex of child .................... ...................... .................... ......................(1)

(ii)

What name is given to the process when a cell divides to produce gametes? ...........................................................................................................................(1)

(iii)

How many pairs of chromosomes are there in each human body cell? ...........................................................................................................................(1)

(iv)

How many chromosomes are present in a human ovum? ...........................................................................................................................(1)

43

(b) (i) Give two advantages to living things of reproducing sexually rather than asexually. ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(2)

(ii)

The genetic diagram shows two parents and three children.

K ey U n a ffe c te d m a le A ffe c te d m a le U n a ffe c te d f e m a leOnly the son has cystic fibrosis, which is caused by a recessive allele. What conclusion may be made about the parents genes? ........................................................................................................................... ...........................................................................................................................(1) (Total 7 marks)

39.

(a)

Balance the following equation for photosynthesis. ............. CO2 + ............. H2O C6HI2O6 + ............. O2(1)

(b)

Give two conditions necessary for photosynthesis apart from a suitable temperature range and the availability of water and carbon dioxide. 1. ................................................................................................................................. 2. .................................................................................................................................(2)

44

(a)

Plants have leaves which contain guard cells and palisade cells. Explain how each of these kinds of cell assists photosynthesis. Guard cells ............................................................................................................... .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................(2)

Palisade cells ............................................................................................................ .................................................................................................................................... .................................................................................................................................... ....................................................................................................................................(2)

(d)

Glucose is a product of photosynthesis. Give three uses which green plants make of glucose. 1. ................................................................................................................................. 2. ................................................................................................................................ 3. .................................................................................................................................(3) (Total 10 marks)

40.

The diagrams show a cheek cell from a human and a leaf cell from a plant.

C h e e k c e ll

L e a f c e ll

45

(a) (i) (ii)

The two cells have a number of parts in common. On the cheek cell, label three of these parts which both cells have.(3)

In the table, write the names of the three parts you have labelled above and describe the main function of each part. Part .................................. .................................. ..................................(3)

Function

(b)

Blood contains white cells and red cells. State the function of each type of cell in the blood. White cells ................................................................................................................. ..................................................................................................................................... Red cells .................................................................................................................... .....................................................................................................................................(2) (Total 8 marks)

41.

(a)

(i)

Complete the word equation for the process of aerobic respiration. + ........................... carbon dioxide +(1)

Glucose water (ii)

Which organ removes carbon dioxide from your body? .................................................................................................................(1)

46

(b)

Use names from the box to complete the two spaces in the passage. carbon dioxide lactic acid nitrogen oxygen water

Anaerobic respiration can occur when an athlete does vigorous exercise. This is because there is not enough ....................................................... in the body. The product of anaerobic respiration is ................................................................. .(2) (Total 4 marks)

42.

In the cell shown in the diagram as a box, one chromosome pair has alleles Aa. The other chromosome pair has alleles Bb. The cell undergoes meiosis. (a) Complete the diagram of the four gametes to show the independent assortment, or reassortment, of genetic material during meiosis. A a B b

(2)

47

(b)

If the cell undergoes mitosis instead of meiosis, draw the two daughter cells which result to show the chromosomes in each.

A a B b

(2)

(c)

State the number of chromosomes in: (i) a normal human cell; ...........................................................................................................................(1)

(ii)

a human gamete; ...........................................................................................................................(1)

(iii)

the daughter cell from mitosis of a human cell. ...........................................................................................................................(1) (Total 7 marks)

48

43.

Two heterozygous parents, with alleles Rr, produce offspring. (i) Draw a genetic diagram to show all the possible arrangements of alleles in their offspring.

(2)

(ii)

One of the offspring is dominant homozygous. What is the chance of this occurring? .....................................................................................................................................(1) (Total 3 marks)

44.

Oxygen from our lungs is carried, by our blood, to cells in our body where aerobic respiration takes place. (i) Complete the two spaces to balance the chemical reaction for aerobic respiration. C6H12O6 + 6O2 ....... CO2 + ...... H2O(1)

(ii)

Name the substance with the formula C6H12O6. .....................................................................................................................................(1)

(iii)

Name the structures in the cytoplasm of our cells where aerobic respiration takes place. .....................................................................................................................................(1) (Total 3 marks)

49

45.

The information in the table compares two farms. Both are the same size, on similar land, close to one another and both are equally well managed. Name of farm Activity Energy value of food for humans produced in one year 3285 million kJ 365 million kJ Number of people whose energy requirements can be met by this food 720

Greenbank Farm Oaktree Farm

Grows food for humans Grows food for animals on the farm which become food for humans

80

(a) Use this information to work out the average daily human energy requirement in kilojoules (kJ) per day. ..................................................................................................................................... ..................................................................................................................................... Energy requirement = ................................. kJ/day(2)

(b)

The figures show that farms like Greenbank Farm can be nine times more efficient at meeting human food energy requirements than farms such as Oaktree Farm. (i) The food chain for Greenbank Farm is: vegetation humans What is the food chain for Oaktree Farm? ...........................................................................................................................(1)

50

(ii)

Explain why Greenbank Farm is much more efficient at meeting human food energy requirements. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ...........................................................................................................................(3)

(c)

The human population has been increasing rapidly throughout this century. It is now about 6 billion and is still growing. What does the information in this question suggest about likely changes in the human diet which may need to occur during the coming century? Explain your answer. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(4) (Total 10 marks)

51

46.

(a)

The air you breathe in and the air you breathe out are different.

Use the names of gases from this box to complete the three spaces. argon carbon dioxide nitrogen oxygen water vapour

Compared to the air you breathe in, the air you breathe out contains: more ..................................................................................................................... more ..................................................................................................................... less ........................................................................................................................(3)

(b)

The process of aerobic respiration takes place in your cells. (i) Complete the space in the word equation for this process. ........................ + oxygen carbon dioxide + water(1)

(ii)

Complete the space to give the main energy transfer which takes place in this process. chemical energy ............................... energy(1)

(iii)

What is the name of the organ where oxygen from the air passes to your blood? ...........................................................................................................................(1)

52

(c)

The athlete is taking part in vigorous exercise.

Complete the two spaces in the passage. The cells in our muscles respire anaerobically during vigorous exercise. This results in ........................................debt and the production of ....................................... acid.(2) (Total 8 marks)

53

47.

The diagram shows the digestive system.

(a)

Complete the following sentences about digestive enzymes. (i) Amylase works in the ........................................... where it is involved in the digestion of ................................................... to ............................................. .(3)

(ii)

Lipase works in the ............................................... where it is involved in the digestion of ................................................... to ............................................. .(3)

(b)

Which gland produces: (i) amylase; ..........................................................................................................................(1)

54

(ii)

lipase? ..........................................................................................................................(1) (Total 8 marks)

48.

(a)

The diagram shows a typical plant cell.

Complete the three spaces. C e l l w a l l m a d e o f ........................................ ........................................ c o n ta in i n g c e ll s a p N u c le u s ........................................ c o n ta in i n g c h lo r o p h y ll

(3)

(b)

Organisms have cells which produce enzymes. (i) Name the single-celled organisms which produce the enzymes for bread making. ...........................................................................................................................(1)

55

(ii)

On the axes sketch a graph to show how the speed of an enzyme reaction changes with temperature. Mark, with an X on the temperature axis, the optimum temperature for the action of the enzyme. F ast

Speed of re a c tio n

S lo w Low T e m p e ra tu re H ig h(2)

(iii)

In the box, ring the temperature which is the optimum temperature for an enzyme which acts inside the human body. 23 C 29 C 31 C 37 C 41 C 43 C 47 C 53 C(1)

(iv)

Complete the sentence. At temperatures much higher than its optimum temperature an enzyme is ........................................................ .(1)

(c)

Enzymes affect certain chemical reactions in living things. (i) What effect do enzymes have on these reactions? ........................................................................................................................... ...........................................................................................................................(1)

(ii)

Complete the sentence.56

When an enzyme affects a chemical reaction it is acting as a biological .......................................................... .(1) (Total 10 marks)

49.

One of Mendels original experiments was to cross pure-breeding, red-flowering pea plants with pure-breeding white-flowering pea plants. The next year he grew the seed he had collected. This first generation, F1, of pea plants all had red flowers. Mendel then made each flower on these plants self-pollinate. He collected the seed from these flowers and grew them. The second generation, F2, gave the following result: 705 red-flowering plants and 224 white-flowering plants.

(a)

Which flower colour is due to the recessive allele? .....................................................................................................................................(1)

(b)

Draw a genetic diagram to show the inheritance of flower colour in the first generation (F1) of plants. Use the letters r and R to represent the alleles for flower colour.

(3)

(c)

Explain why Mendel made the first generation of plants self-pollinate. .....................................................................................................................................57

..................................................................................................................................... .....................................................................................................................................(2)

(d)

If Mendel had taken any two of his white-flowering peas and crossed them, what would have been the colour of the flowers of the next generation of plants? .....................................................................................................................................(1)

(e)

It is very difficult to get red-flowering pea plants that breed true. Explain why you cannot guarantee to breed, by self-pollination, pea plants that only have red flowers. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2) (Total 9 marks)

50.

The genetic diagram shows how the chromosomes divide and combine in human reproduction. X X X Y

X

X

X

Y

X X

X X

X Y

X Y

58

(a) (b)

Draw circles around the symbols for the two male gametes.(2)

State the chance of a child being a girl. .....................................................................................................................................(1)

(c)

(i)

How many pairs of chromosomes are there in a human body cell?(1)

..........................................................................................................................

(ii)

How many chromosomes are there in a human egg cell? ..........................................................................................................................(1)

(d)

Chromosomes contain genes. From what substance are genes made? .....................................................................................................................................(1)

(e)

In the process of mitosis, how do the number of chromosomes in the daughter cells compare to that in the original cell? .....................................................................................................................................(1) (Total 7 marks)

51.

(a) The diagrams show what happens to the shape of a plant cell placed in distilled water.

T h e c e ll s w e lls

P la n t c e ll

T h e c e ll b e c o m e s tu rg id

59

(i)

Explain why the cell swells and becomes turgid. Name the process involved. .......................................................................................................................... .......................................................................................................................... ..........................................................................................................................(2)

(ii)

Give one feature of the cell wall which allows the cell to become turgid. ..........................................................................................................................(1)

(b)

Describe the change which will occur if a piece of peeled potato is placed in a concentrated sugar solution and explain why this change occurs. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 6 marks)

60

52.

During the last hundred years many species of whales have been over-hunted. This has led to a dramatic decrease in their numbers. The graph shows the catches of two of these species, Fin whales and Sei whales, between 1956 and 1970. 35 000 30 000 25 000 C a tc h o f w h a le s 1 5 0 0 0 10 000 5 000 019 19 19 19 62 56 58 60

F in w h a le

20 000

S e i w h a le

S e i w h a le19 64

F in w h a le19 19 19 70 66 68

Y ear (a) When did over-hunting begin to affect the Fin whale population?(1)

.....................................................................................................................................

(b)

Complete the sentence. When a species is over-hunted many adults are killed. The population numbers fall dramatically because the death rate is far greater than the .........................................................(1)

(c)

(i)

In what year were the catches of Fin whales and Sei whales the same?(1)

.......................................................................................................................... (ii) Between 1963 and 1964 how did the catches of Fin whales and Sei whales alter? Fin whales ........................................................................................................ Sei whales ........................................................................................................(1)

61

(d)

Suggest why the catches of Sei whales increased between 1956 and 1964. ..................................................................................................................................... .....................................................................................................................................(1) (Total 5 marks)

53.

Information is passed to target organs in the body by hormones. (a) (i) How do hormones travel around the body?(1)

..........................................................................................................................

(ii)

What name is given to the organs that secrete hormones? ..........................................................................................................................(1)

(b)

Explain the cause of diabetes and how it is controlled. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(3) (Total 5 marks)

54.

(a)

Use words from the box to complete the sentences about the water cycle. boils melts condenses rain sea evaporates Sun freezes wind

62

Water .............................. from the surface of the ............................ . Heat from the ................................. speeds up this process and so does the .................................. . Water vapour in the atmosphere cools down and ........................ to form billions of tiny water droplets. Some of the droplets join together and fall as ........................ .(6)

(b)

The diagram shows some processes in the carbon cycle. S u b s ta n c e X in th e a tm o sp h e re

P h o to sy n th e s is (P ro c e ss A )

R e s p ira tio n , b u rn in g and decay (P ro c ess C )

B u rn in g (P ro c e ss E )

F o rm a tio n o f o il (P ro c e ss D ) F o rm a tio n o f o th e r carb o n co m p o u n d s in p la n ts (P ro c e s s B )

(i)

What is the name of substance X? ..........................................................................................................................(1)

(ii)

Which process, A, B, C, D or E, takes the longest and approximately how long does it take? ..........................................................................................................................(2) (Total 9 marks)

63

55.

A food chain in the North Atlantic Ocean is: diatoms small fish large fish

The graphs show how over a year: the population size of diatoms in the North Atlantic varies; the light intensity alters; the concentration of nitrate and phosphate minerals alters.

C o n c e n tra tio n o f n itra te s a n d p h o s p h a te s

D ia to m p o p u la tio n s iz e

L ig h t in te n s ity

A

Sp rin te r g

Su

(a) Explain why the light intensity is a major factor in controlling the numbers of diatoms. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2)

W in

W ut um n

m m er

in te r

(b)

(i) Suggest two reasons why the population of diatoms decreases between spring and summer. 1. ...................................................................................................................... .......................................................................................................................... 2. ...................................................................................................................... ..........................................................................................................................(2)

64

(ii)

Give two reasons why the population of diatoms decreases in autumn. 1. ..................................................................................................................... .......................................................................................................................... 2. ...................................................................................................................... ..........................................................................................................................(2)

(c)

Use the information on the graph to suggest what change causes the number of diatoms to increase in the late summer. Give a reason for the change. ..................................................................................................................................... ..................................................................................................................................... .....................................................................................................................................(2) (Total 8 marks)

56.

(a)

How many pairs of chromosomes are there in a body cell of a human baby?(1)

.....................................................................................................................................

(b)

Place the following in order of size, starting with the smallest, by writing numbers 1 4 in the boxes underneath the words.

ch ro m o so m e

n u c le u s

gene

c e ll

(1)

65

(c)

For a baby to grow, its cells must develop in a number of ways. Explain how each of the following is part of the growth process of a baby. (i) Cell enlargement ..........................................................................................................................(1)

(ii)

The process of cell division by mitosis .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... ..........................................................................................................................(3)

(d)

Why is cell specialisation (differentiation) important for the development and growth of a healthy baby from a fertilised egg? ..................................................................................................................................... .....................................................................................................................................(2) (Total 8 marks)

66

57.

Compare the efficiency of these two food chains. Food chain A Food chain B grain humans grain bullocks humans

In your answer, make full use of the following data. Food Grain Grain Bullock Consumer Human Bullock Human 9% 12% 10% Percentage of available energy transferred as useful energy

One kilogram of grain has 80 000 kJ of available energy. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................(Total 4 marks)

67

58.

The diagram shows one pair of chromosomes from the fruit fly.

P a rt w h ic h d e te rm in e s b o d y c o lo u r

N o rm a l w in g s

P a rt w h