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Sample Paper Biology

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1 This question is about microorganisms.

1(a) Complete the diagram below to show the structure of a bacterial cell.

[3 marks]

1(b) Bacterial cells contain no nucleus. What name is given to organisms made of cells

with no nucleus?

[1 mark]

1(c) Some bacteria cause diseases. What name is given to organisms that cause

disease?

[1 mark]

1(d) Which of the following statements about viruses is not true?

Tick (✓) one box.

[1 mark]

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Tick (✓)

Viruses require a host to reproduce.

Viruses are much larger than bacteria.

Viruses do not feed, respire or grow.


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2 During photosynthesis, plants convert light energy to chemical energy.

2(a) Give a balanced chemical symbol equation to represent the chemical reaction that

takes place.

[2 marks]

2(b) Give the name of the green pigment in leaves which absorbs light.

[1 mark]

2(c) List the three factors which control the rate of photosynthesis in a plant.

[3 marks]

1.

2.

3.

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.................... + ........................................ + ....................light


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3 Outline the differences between sexual and asexual reproduction in plants.

Your answer should explain why one method of reproduction leads to genetic

variation whilst the other does not.

[6 marks]


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4 The numbers and distribution of organisms within an ecosystem are affected by biotic

and abiotic factors.

4(a) State whether the following are biotic or abiotic factors.

(i) Availability of food

[1 mark]

Answer

(ii) Pollution levels

[1 mark]

Answer

(iii) Light intensity

[1 mark]

Answer

4(b) Feeding relationships within an ecosystem can be represented by a food chain.

The diagram below shows a simple food chain.

(i) Green plants create their own food via photosynthesis.

What term is used to describe an organism at the start of a food chain which creates

its own food?

[1 mark]

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Caterpillar Blue Tit SparrowhawkGreen

plants


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(ii) When animals and plants die, decomposers may begin the process of breaking down

the dead material.

What type of organism is a decomposer and why are they an important part of an

ecosystem?

[2 marks]


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5 A student wants to investigate the distribution of clover plants in a playing field in a

local park.

They used the following procedure:

1. Place a 0.5 m × 0.5 m quadrat in a section of the playing field

2. Count the number of clover plants inside the quadrat

3. Repeat the first two steps in three other nearby areas of the playing field.

5(a) Suggest two ways the student could improve their procedure.

[2 marks]

1.

2.

5(b) The student calculates that there are an average of four clover plants per square

metre in the playing field.

The playing field is a 120 m × 40 m rectangle.

(i) Estimate the total number of clover plants in the whole playing field using these

results.

[2 marks]

Answer

(ii) The playing field is used by a local football team every week. The student placed

quadrats in areas of the field that were less damaged by the football team.

What effect is this likely to have on the student’s estimate of the total number of clover

plants?

Give a reason for your answer.

[2 marks]


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6 Many biologists believe that genetically modified plants could greatly improve global

food production and help to mitigate world hunger.

Plants can be genetically modified to have certain characteristics, such as greater

cold resistance.

6(a) Suggest three other characteristics that could be implemented into crops to provide

higher yield.

[3 marks]

1.

2.

3.

6(b) Explain how plants can be genetically modified using Agrobacterium as a vector.

[5 marks]


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7 Stem cell therapy can be used to treat many diseases.

7(a) Give one source of adult stem cells.

[1 mark]

7(b) Scientists are able to isolate and culture embryonic stem cells.

Suggest one advantage and one disadvantage of using embryonic stem cells rather

than adult stem cells to treat disease.

[2 marks]

Advantage:

Disadvantage:


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8 A student is investigating the carbon dioxide content of inhaled air.

They set up the following apparatus.

8(a) Describe what the student would observe as they breathe in and out.

[3 marks]

8(b) The student repeats the experiment after 5 minutes of vigorous exercise.

Explain how this may affect the experiment.

[2 marks]

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9 Smoking can cause a number of respiratory diseases in humans and is linked with

other conditions such as coronary heart disease.

9(a) Explain how smoking can cause a build-up of mucus in the air passages which may

lead to respiratory diseases such as bronchitis.

[4 marks]

9(b) Smoking also causes emphysema.

Explain how an emphysema sufferer’s lungs differ from those of a healthy person,

and identify the consequences of these differences.

[4 marks]


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10 The growth of a plant in response to an external stimulus is known as tropism.

10(a)(i) Explain what is meant by the term geotropism.

[1 mark]

(ii) Give an example of a part of a plant that exhibits positive geotropism.

[1 mark]

(iii) Give an example of a part of a plant that exhibits negative geotropism.

[1 mark]

10(b) The diagram below shows the action of phototropism in a plant shoot.

Explain the role of auxin in phototropism.

[3 marks]

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11(a) Describe the process of vasodilation and explain how it regulates body temperature in

hot conditions.

[3 marks]

11(b) Explain why sweating is not very effective at cooling the body down in humid

conditions.

[3 marks]


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12 Sulfur dioxide (SO2) and nitrogen oxides (Nox) are both pollutant gases.

12(a)(i) Give an example of a natural source of sulfur dioxide

[1 mark]

(ii) Give an example of a natural source of nitrogen oxides.

[1 mark]

12(b) Explain how pollutant gases such as sulfur dioxide and nitrogen oxides lead to the

formation of acid rain.

[2 marks]

12(c) Identify two consequences of acid rain.

[2 marks]

12(d) What term is used to describe species such as lichen, the populations of which are

sensitive to different levels of pollutants.

[1 mark]

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12(e)(i) Carbon dioxide is a greenhouse gas which is released when fossil fuels are burned.

Explain how human contributions to greenhouse gases such as carbon dioxide can

lead to global warming.

Your answer should include a description of the greenhouse effect.

[6 marks]

(ii) State two consequences of global warming.

[2 marks]


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13 A schematic representation of the flow of nitrogen through the ecosystem is shown

below.

13(a)(i) Fill in the missing boxes to show the nitrogen-containing compounds at each stage in

the nitrogen cycle.

[2 marks]

(ii) What type of organisms are responsible for converting the protein in plants and

animals to ammonia?

[1 mark]

13(b) The nitrogen-fixing bacteria in root nodules exist in a mutualistic relationship with the

plant.

Explain how both the bacteria and the plant benefit from this relationship.

[2 marks]

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13(c) The proteins in plants and animals both contain nitrogen.

Give two other examples of biological molecules that contain nitrogen.

[2 marks]

1.

2.

13(d)(i) Explain why farmers need to add fertilisers to the soil to rebalance the nitrogen levels

when growing crops.

[3 marks]

(ii) Suggest one advantage and one disadvantage of using inorganic fertilisers over

organic fertilisers.

[2 marks]

Advantage:

Disadvantage:


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14 This question is about cell division.

14(a) Outline what happens during the first two stages of cell division by mitosis.

Your answer should include the names of each stage.

[4 marks]

14(b) Cells formed by mitosis are diploid.

What is meant by the term diploid?

[1 mark]

14(c) Describe what happens during the first two stages of meiosis.

[2 marks]

End of questions

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