Science Homework: Due 14th May

Name: _____________________________

Q1.          (a)     The animals drawn below all have backbones.

                                                                                                        not to scale

(i)      What word describes animals with a backbone?
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1 mark

(ii)     There are five groups of animals with a backbone. Only four groups are shown above
Give the name of the missing group
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1 mark

(b)     The drawing below shows the human backbone. It is made up of a number of small bones.
                                      
          Why is it an advantage that the backbone is made up of small bones rather than one long bone?
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1 mark

(c)     The drawing below shows two small bones from the backbone.
          
          Between the small bones there is a material called cartilage.
Cartilage is softer than bone.
Give one advantage of having a softer material between the bones.
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1 mark

(d)     The diagram below shows the bones and two muscles of an arm.

          The biceps and triceps are muscles which raise and lower the forearm.
What happens to the biceps and triceps to raise the forearm?
the biceps ...........................................................
the triceps ...........................................................
1 mark
maximum 5 marks

 

Q2.          The drawings show a human, a chaffinch, a dog and a whale.

not to scale

          One of these animals is a bird. The other three are mammals.
(a)     Which group do all four animals belong to?
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1 mark

(b)     The drawings below show the bones of the front limbs of the four animals.
Some of the bones of the human limb are labelled.

not to scale

          On the drawings, label:
(i)      the ulna of the chaffinch;
1 mark
(ii)     the radius of the dog;
1 mark
(iii)     the humerus of the whale.
1 mark

(c)     Describe how the shape of the front limb of the whale is adapted for moving in water.
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1 mark

(d)     The bones of birds are hollow. How does this help birds to fly?
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1 mark
Maximum 6 marks

 

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          The water snake Natrix sipedon lives on small islands in Lake Erie in North America and on the nearby mainland.
          The colour pattern on the body of the snakes is inherited. There are three body patterns.

          A survey of the snakes on the islands gave the following results:

(a)     (i)      Which body pattern seems to improve the chances of survival to adulthood?
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1 mark

(ii)     Explain how camouflage helps snakes to survive.
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1 mark

          There is much more vegetation on the mainland than on the islands.
Most of the snakes on the mainland are strongly banded.

          Snakes from the mainland interbreed with snakes on the islands.
(b)     (i)      Suggest how the proportions of strongly banded and unbanded snakes on the islands would change over a number of years if this interbreeding stopped.
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1 mark

(ii)     Explain your answer with reference to the genes for body pattern.
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2 marks
Maximum 5 marks

 

Q4.          Human twins may result from:
either          the fertilisation of two separate eggs, released together;
or                the fertilisation of a single egg which then divides into two cells, 
each cell developing into a baby.

The table below gives information about three sets of twins.
 
sets of twins	name	blood group	eye colour	mass in kg	sex	
set 1	Sasha
Ninvata	A
AB	brown
brown	37
37	female
female	
set 2	Lucy
Tom	O
O	brown
brown	38
32	female
male	
set 3	Fred
Jack	O
O	blue
blue	34
36	male
male	

(a)     Which one of the characteristics below cannot be used to decide whether twins have come from a single egg or two eggs?
Tick the correct box.
 
blood group		mass		
eye colour		sex		

1 mark

(b)     (i)      Use the information in the table to suggest which set of twins could have come from a single egg.
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1 mark
(ii)     Explain why you have suggested this set of twins.
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1 mark

(c)     The graph shows the number of sets of single-egg and two-egg twins born to mothers of different ages.

Two hormones, produced by the pituitary gland, cause eggs to develop in the ovary.
Which statement could explain the results shown on the graph?
Tick the correct box.
 
As women get older, their
ovaries do not respond to
either of the hormones.		As women get older, they are
less likely to give birth to single-egg twins.		
As women get older, they produce more of each hormone.		As women get older, their ovaries release two eggs every month.		

1 mark

(d)     There are two types of cell division, meiosis and mitosis.
(i)      Why are eggs and sperms produced by meiosis?
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1 mark

(ii)     Why does a fertilised egg divide by mitosis?
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1 mark
Maximum 6 marks

Q5.          The drawings show five different lichens which grow on rocks or trees.

Identify lichens A, C and D using the key below.
1.      The lichens grow on tree bark...............        Go to 2
The lichens grow on rocks ...................        Go to 4
2.      They grow flat against the surface .......           Parmelia subrudecta
They have branches which
grow away from the surface..................        Go to 3
3.      They have long dangling branches ......            Usnea
They have short branches ...................         Evernia

4.      They are bright orange ........................          Xanthoria
They are pale grey-green ....................          Parmelia saxatilis
         The name of Lichen A is ......................................................................
         The name of Lichen C is ......................................................................
         The name of Lichen D is ......................................................................
Maximum 3 marks

 

Q6.          Andrew put his rabbit’s cage on the grass.

          A week later, the grass under the cage had turned yellow.

(a)     Give one reason why the grass had turned yellow.
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1 mark

(b)     Andrew wanted to test why the grass had turned yellow. He put two sheets of plastic just above another patch of grass. One sheet was black and the other sheet was clear.

          A week later, the grass under the black sheet was yellow. The grass under the clear sheet was green.

(i)      Explain why he used the clear plastic sheet as well as the black sheet.
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1 mark

(ii)     Andrew left the black sheet there for several more weeks.
What happened to the grass under it?
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1 mark

(c)     Tick the boxes by two things which both rabbits and grass plants can do.
they eat                                            
they grow                                         
they move from place to place        
they reproduce                                 
they breathe in and out                    
2 marks
Maximum 5 marks

 

Q7.          (a)     The drawings below show a stoat in summer and in winter.

stoat in summer                                          stoat in winter

          In winter the ground is often covered by snow or frost. During this part of the year a stoat’s fur is white.
Suggest two ways its white coat helps a stoat to survive in the winter.
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2 marks

(b)     The diagram shows the family tree for a family of rabbits.

          Use words from the list below to complete the sentences.
adapt            cytoplasm           genes          grow          inherit
letters          membrane          mutate         nuclei
          Rabbits have the same fur colour all year round.
          Young rabbits ............................................ fur colour from their parents.
          Information about fur colour is passed on from one generation to
          the next in the form of ................................... in the ..................................... of
          an egg and sperm.
3 marks
Maximum 5 marks

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          Genetic engineering can be used to prepare human growth hormone using bacteria. The diagrams represent six stages in the process. They are not in the order, and they are not drawn to scale.

(a)     Put the stages shown in the diagrams above in the correct order. Two stages have already been put in for you.

1 mark

(b)     Give two reasons why these bacteria are used in this process.
1. ..................................................................................................................
    ..................................................................................................................
1 mark
2. ..................................................................................................................
    ..................................................................................................................
1 mark
Maximum 3 marks