AQA GCSE Trilogy Biology Paper 2 Foundation November 2020 question paper 8464/B/2F

This question is about reproduction.

Which two statements are true for sexual reproduction in humans? Tick (✓) two boxes.

Humans reproduce by sexual reproduction. Complete Figure 1 to show the inheritance of sex.

Figure 1

Draw a ring around the genotype of all male children in Figure 1.

When children reach puberty, reproductive hormones cause changes in their bodies. Draw one line from each hormone to the change the hormone causes at puberty.

Change the hormone Hormone causes at puberty

A woman does not want to become pregnant. She considers two methods of contraception.

Draw one line from each method of contraception to how the method prevents pregnancy.

Method of contraception How the method prevents

Give one advantage and one disadvantage of taking oral contraceptives to prevent pregnancy.

Ammonites became extinct millions of years ago. Figure 2 is a photograph of a fossil ammonite. Figure 3 is a drawing of what scientists think a living ammonite looked like.

How was the fossil in Figure 2 formed? Tick (✓) one box.

Suggest why scientists are not certain what living ammonites looked like.

Figure 4 shows when two different types of organism were alive on Earth.

How many millions of years ago did ammonites become extinct? Use Figure 4.

Trilobites lived on Earth for 270 million years. Calculate how much longer ammonites lived on Earth than trilobites. Use Figure 4.

Suggest two factors which may have caused ammonites to become extinct.

The fossil record provides evidence for the theory of evolution by natural selection.

Which scientist proposed the theory of evolution by natural selection? Tick (✓) one box.

Figure 5 shows ammonite fossils from three different time periods.

How do the fossils in Figure 5 give evidence for the theory of evolution by natural selection? Tick (✓) one box.

Mineral ions are important chemicals in an ecosystem.

Plants take in nitrate ions dissolved in water. Which part of a plant takes in nitrate ions?

Name two chemicals that are cycled between plants, the soil and the air. Do not refer to nitrogen or nitrates in your answer.

All the chemicals in a plant are recycled when the plant dies. Describe how:

• microorganisms recycle chemicals

• the chemicals are used again by new plants.

Homeostasis regulates the internal conditions of the human body.

Which two processes are regulated by homeostasis? Tick (✓) two boxes.

Hormones are produced by glands in the endocrine system. Each hormone has an effect on a target organ. Figure 6 shows glands of the endocrine system.

What is the name of gland A ? Tick (✓) one box.

Before eating a sugar-coated cereal a person had a blood glucose concentration of 5.2 mmol/dm³ Soon after eating the cereal the person had a blood glucose concentration of 8.4 mmol/dm³

Calculate the increase in the blood glucose concentration.

The person needed medication to decrease their blood glucose concentration. Suggest what disorder the person has.

There is a problem with the hormone control of the person. What is the problem? Tick (✓) one box.

The person:

• works in an office

• drives to work

• is overweight

• watches the television and reads every night

• drinks a hot chocolate every night.

Suggest two lifestyle changes the person could make to help treat their disorder.

This question is about biodiversity. A farmer:

• grows only wheat crops

• has used all his small fields to make a few large fields

• cuts down trees in his woodlands to burn as fuel.

What are two ways the farmer could increase biodiversity on his farm? Tick (✓) two boxes.

Students investigated the effect of cutting down trees in the woodland. This is the method used.

1. Mark out a 10 m by 10 m area where trees have been removed.

2. Place a 1 m × 1 m quadrat at six random positions in the area.

3. Record the number of plant species present.

4. Record the number of invertebrate species seen among dead leaves on the ground.

5. Repeat steps 1 to 4 in an area where there are trees.

Suggest one improvement the students could make to their method.

The students made this prediction: ‘There will be more invertebrate species living in the area where there are trees.’

Explain why the students’ prediction may be correct.

Table 1 shows the students’ results.

The students decided that one result was anomalous. Draw a ring around the anomalous result in Table 1.

How does removing trees affect the number of invertebrate species living among the dead leaves on the ground? Use Table 1.

There were more plant species growing in the area where there were no trees. Explain why.

This question is about DNA and genes.

Which diagram represents a DNA molecule? Tick (✓) one box.

Describe the structure of a DNA molecule.

A gene is a small section of DNA on a chromosome. Complete the sentences.

A gene codes for a particular sequence of. This sequence makes a specific.

What is meant by the term genome?

The complete human genome is now known. Which important scientific advance was made using knowledge of the human genome? Tick (✓) one box.

A student found six different snails of one species in his garden. Figure 7 shows the snails.

All the snails are different. What scientific term describes differences in characteristics between individuals of a species?

A change in DNA has caused snail P to be very different from the other five snails. Suggest why there might be an increasing number of snails similar to snail P in each future generation.

Human reactions are a response to an external change.

Reflex actions help to protect the body against damage. Figure 8 shows the nervous pathway for a reflex action.

A stimulus from the hot pan will cause the muscle in the arm to contract and move the finger away. Describe how the stimulus from the hot pan reaches the muscle in the arm.

A student investigated whether using the right hand or the left hand had an effect on reaction time. The student only tested right-handed people.

Describe a method for the student’s investigation. Include details of the test you would use for reaction time.

A different student carried out an investigation to see if playing tennis improved reaction time. The student used two groups of six people. Table 2 shows the results.

Calculate mean value X in Table 2.

What is the dependent variable in the student’s investigation?

The student concluded: ‘Playing tennis improves reaction time.’

Give one piece of evidence which supports the conclusion.

Give one piece of evidence which does not support the conclusion.