CEE_PP_2000_Biology_Ans

1.    a) A few drops of orange iodine solution turned blue-black when added to a food. This food contained

fat           protein           starch           vitamin C

 (1)

b) The food component which is used for insulation is

carbohydrate           fat           minerals           protein

 (1)

c) Glucose is transported in the blood

along the walls of the capillaries           dissolved in the plasma fluid

inside red blood cells           inside white blood cells

 (1)

d) The cell that is a gamete is a

kidney cell           pollen grain           red blood cell           sperm cell

 (1)

e) The waste material made by a fetus is

carbon dioxide           glucose           oxygen           protein 

 (1)

f) Many people who smoke cigarettes eventually develop severe difficulties when breathing. This is because cigarette smoke

makes the blood sticky                                                  reduces the surface area of the lungs

reduces the flow of blood away from the lungs           travels in the blood to the heart

 (1)

g) The process which adds oxygen to the air is

combustion           photosynthesis          precipitation           respiration

 (1)

h) Vertebrates include

amoebae           amphibians           arthropods           fungi

 (1)

i) alga --> water flea --> stickleback --> pike. There are four types of organism in this food chain. The producer is the

alga           pike           stickleback           water flea

 (1)

 

2.    The diagram below shows part of a human lung

(a) Name the gas which human cells produce during aerobic respiration.

 (1)

(b) What happens to oxygen gas when it reaches an alveolus?

 (1)

(c) How is oxygen transported in the blood?

 (1)

(d) There are many alveoli in the lungs, which have a large surface area for the exchange of gases. Why is this important for large active animals such as humans?

 (2)

 

 

3.    The apparatus was set up as shown below.

The beaker was placed in the dark for two hours and the amount of oxygen dissolved in the water was recorded. The light was then switched on and the amount of oxygen dissolved in the water was recorded for another two hours.

The results are shown on the graph below.

(a)   (i) What happens to the amount of oxygen dissolved in the water when the plant is in the dark?

 (1)

(ii) Suggest an explanation for this observation.

 (2)

(b)   (i) What happens to the amount of oxygen dissolved in the water when the light is switched on?

 (1)

(ii) Suggest an explanation for this observation.

 (2)

 

 

4.    (a) State two changes which occur in a boy's body at puberty.

1.       (1)

2.       (1)

(b) Name two changes which occur in a baby when it is born.

1.       (1)

2.       (1)

(c) The leaves of a deciduous tree fall in the autumn. Describe two changes which occur in such a tree in the spring.

1.       (1)

2.       (1)

 

 

5.    Why is it important to clean our teeth? What is the best way of doing it?

Why we clean our teeth:

 (2)

How we should clean our teeth:

 (1)

 

 

6.    Using words from the list below, complete the sentences in the following passage about human reproduction. Each word may be used once, more than once, or not at all.

egg      fluid      oviduct      oxygen      placenta      uterus      vagina

An  is produced by the ovary. Fertilisation normally occurs in the . A few days later, the developing embryo becomes attached to the wall of the . During its development the embryo receives food and  through the . The embryo is protected from mechanical shock by  contained in a bag.

(6)

 

 

7. The diagram shows the cells in a section of a leaf. This question is about photosynthesis which occurs inside the cell labelled X.

(a) Photosynthesis uses up carbon dioxide from the air which enters the leaf. Draw a line on the diagram showing the possible route that a carbon dioxide molecule might take when moving from the air outside the leaf to cell X.

(2)

(b) The chloroplasts (W) contain a green substance called chlorophyll. What is the function of chlorophyll?

 (1)

 
 

8.    Caroline does an experiment to find. out if an earthworm gives out carbon dioxide when it respires. Her method is shown below.

(a) What is the purpose of the limewater in flask A?

 (1)

(b)   (i) What would you expect to happen to the limewater in flasK B?

 (1)

(ii) What conclusion would you draw from your observation?

 (1)

(c) Caroline realises that her experiment needs a control.

(i) Why is the control necessary?

 (1)

(ii) Suggest a suitable control.

 (1)

(d) Name two substances which the earthworm needs in order to respire.

1.       (1)

2.       (1)

 

 

9.    The diagram shows a mouthful of food travelling down the gullet (oesophagus) towards the stomach. The muscles of the gullet contract just above the swallowed food. The arrows show where the muscles contract.

(a) Explain how the muscles of the gullet help move food towards the stomach.

 (2)

The walls of the stomach contain muscles which contract to churn up the food inside the stomach. They also contain cells which make hydrochloric acid. This helps the digestion of proteins.

(b) Sometimes the stomach produces too much acid. One remedy for acid indigestion is to swallow a mild alkali (such as sodium hydrogen carbonate). Suggest why this is an effective remedy.

 (1)

(c) People who eat their food very quickly often swallow air at the same time as their food. This enters the stomach with the food, and is churned up with the rest of the food, Suggest what happens to this trapped air.

 (1)

 

 

10.    The diagrams below show ten animals. They are not drawn to scale.

 

(a) Name three vertebrates in the diagram.

1.      

2.      

3.       (3)

(b) Name one characteristic which grasshoppers and jellyfish have in common.

 (1)

(c) Mice and rabbits are both mammals. Name one other mammal (it does not have to be in the diagram).

 (1)

(d) Name two characteristics which all mammals have in common.
 (2)

(e) Name two animals in the diagram which lay their eggs in water.

1.      

2.       (2)

(f) Simon has an animal which he thinks is a spider. You think it might be an insect. How could you be sure that it is an insect?

 (2)