AQA GCSE Biology Paper 2 Foundation June 2019 question paper 8461/2F

The nervous system allows a person to detect stimuli.

Draw one line from each stimulus to the sense organ that detects the stimulus.

Moving a hand away from a hot object is an example of a reflex action.

What is a reflex action?

A muscle in the arm moves the hand away from the hot object.

How does the arm muscle do this?

Tick (✓) one box.

Two students investigated the effect of drinking coffee on reaction time.

This is the method used.

1. Student A holds a metre rule just above student B ’s hand, as shown in Figure 1.

2. Student A lets go of the metre rule.

3. Student B catches the metre rule as quickly as possible.

4. Student A writes down the reading from the scale on the metre rule.

5. Students A and B repeat steps 1‒4 another four times.

6. Student B then drinks a cup of coffee.

7. After 15 minutes, students A and B repeat steps 1‒5.

Table 1 shows some of the results.

Figure 2 shows the results after drinking the coffee for tests 3, 4 and 5.

Complete Table 1.

Use results from Figure 2.

The students made the following conclusion:

‘Drinking coffee speeds up reactions.’

Give evidence from Table 1 to support the students’ conclusion.

The students’ conclusion may not be valid.

Suggest two improvements the students could make to their method.

The shape of a person’s earlobes is controlled by a gene.

Figure 3 shows two types of earlobe.

A dominant allele codes for free earlobes.

What is a dominant allele?

Tick (✓) one box.

A man with free earlobes and a woman with attached earlobes have children together.

Complete Figure 4 to show the possible genotypes of the children.

Use the symbols:

E = allele for free earlobes e = allele for attached earlobes

What is the probability that one of the children would have attached earlobes?

Use Figure 4.

Tick (✓) one box.

Figure 5 shows the inheritance of the sex chromosomes, X and Y.

Complete Figure 5 to show the sex chromosomes in the gametes of the man and the woman.

Calculate the probability that the man and the woman’s next child will be a girl with attached earlobes.

Use the equation:

probability of a girl with attached earlobes

= probability of attached earlobes probability of being a girl

Figure 6 shows the production of sperm cells in humans.

Cell A is a normal body cell.

How many chromosomes are there in cell A ?

Tick (✓) one box.

What is the mass of DNA in cell E ?

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What type of cell division produces sperm cells?

Tick (✓) one box.

Sometimes there are errors in copying the genetic material.

What term describes an error in the genetic material?

Tick (✓) one box.

A woman has three children, aged 4, 6 and 9 years.

Why are the children not genetically identical?

In sexual reproduction, a sperm cell fuses with an egg cell to form a new single cell.

An embryo develops from the single cell.

The cell divides three times to produce the embryo.

How many cells are there in the embryo after three cell divisions?

Tick (✓) one box.

Figure 7 shows a different human embryo.

Measure image length X on Figure 7.

Give your answer in millimetres (mm).

The image in Figure 7 has been magnified 500

Calculate the real length of the embryo.

Use the equation:

Give your answer in micrometres (m).

The embryo may not implant in the lining of the uterus.

The embryo will then be lost from the woman’s body several days later.

Explain why the woman may not notice this has happened.

Gardeners sometimes make compost heaps from dead plant material.

The dead plants decay in the compost heap.

Figure 8 shows a compost heap.

The thin layers of soil contain organisms that cause decay.

Which two types of organism cause decay?

Tick (✓) two boxes.

The rate of decay in the compost heap depends on several environmental factors.

Explain how the rate of decay would be affected by:

• an increase in oxygen concentration

• a temperature increase from 5 C to 25 C

Give one environmental factor needed for decay.

Do not refer to oxygen or temperature in your answer.

Dead plant material can also be decayed in a biogas generator.

Figure 9 shows the percentages of the gases found in a sample of biogas.

Gas X is the main fuel gas found in the biogas.

What is gas X ?

Tick (✓) one box.

What is the percentage of gas X in the biogas?

The dead plant material in the compost heap and biogas generator does not decay completely.

Explain why a farmer might spread the remaining dead plant material onto his fields.

Figure 10 shows a flightless bird called the dodo (Raphus cucullatus).

The dodo:

• was 1 m tall

• had a mass of 20 kg

• lived in rainforests on a tropical island

• ate fruits

• made its nest on the ground.

A female dodo laid only one egg each year.

Humans arrived on the island in the year 1507. By 1681 the dodo was extinct.

What is the genus of the dodo?

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Before the arrival of humans, there were no other large animals living on the island.

Suggest two reasons why the dodo became extinct soon after the arrival of humans.

Today, humans are cutting down large areas of tropical rainforests.

Suggest one use of the land after the trees have been removed.

Why does the removal of trees cause an increase in carbon dioxide in the atmosphere?

Tick (✓) two boxes.

What effect would an increase in carbon dioxide in the atmosphere have on global air temperature?

Tick (✓) one box.

‘Sustainable forestry’ reduces the harmful effects of cutting down trees on the environment.

Figure 11 shows a method of ‘sustainable forestry’.

Numbers 1–9 show different parts of a rainforest.

The trees are cut down in the sequence 1 – 2 – 3 – 4 – 5 – 6 – 7 – 8 – 9

• The trees are cut down in only one area at any one time.

• It takes 30 years to cut down the trees in each area.

• The trees in the ‘Old growth’ area are never cut down.

How many years would it take to cut down the trees in all of the numbered areas in Figure 11 ?

The rainforest contains:

• 750 species of trees

• 400 species of birds

• 150 species of butterflies

• many other species of plants and animals.

Explain how the pattern of cutting down trees shown in Figure 11 stops the biodiversity of the rainforest being reduced.

Two of the substances the body excretes are urea and carbon dioxide.

Complete the sentence.

Choose the answer from the box.

A person makes a lot of urea if the person’s diet contains

a lot of.

Why must urea be excreted from the body?

A person produces more carbon dioxide during exercise than when resting.

Complete the sentences.

Choose answers from the box.

The process that makes carbon dioxide is

During exercise, extra carbon dioxide can be removed from the body by increasing

the rate of.

Excess water must also be removed from the body.

If a person sweats a lot, less water will be excreted in the urine.

A healthy person did the same amount of exercise on each of 3 days.

Table 2 shows information for the 3 days.

Complete Table 2.

Choose answers from the box.

Some people have kidney disease.

Kidney disease may be treated by dialysis or by having a kidney transplant operation.

• During dialysis, a person is connected to a machine that filters the blood.

• Each dialysis session lasts about 6 hours.

• The person has several dialysis sessions each week.

Figure 12 shows how dialysis works.

How does urea move out of the blood during dialysis?

Tick (✓) one box.

Which substance in Figure 12 does not pass from the blood into the dialysis fluid?

Give the reason for your answer.

Two people have kidney disease.

• Person A is treated by dialysis.

• Person B has had a kidney transplant.

Figure 13 shows changes in the urea concentration in the blood of each person over 2 weeks.

How many dialysis sessions did person A have each week ?

What happens to the concentration of urea in the blood between dialysis sessions?

Give two reasons why a kidney transplant is a better method for treating kidney disease than dialysis.

Figure 14 shows a food chain in a pond.

Which term describes the Daphnia in this food chain?

Tick (✓) one box.

Draw a pyramid of biomass for the food chain.

Label each trophic level.

Give one reason why the total biomass of the Daphnia in the pond is different from the total biomass of the algae.

Students investigated the size of the population of Daphnia in the pond.

This is the method used.

1. Collect 1 dm³ of pond water from near the edge of the pond.

2. Pour the water through a fine net.

3. Count the number of Daphnia caught in the net.

4. Repeat steps 1–3 four more times.

Table 3 shows the results.

Calculate the mean number of Daphnia in 1 m³ of pond water.

The pond was a rectangular shape, measuring:

• length = 2.5 metres

• width = 1.5 metres

• depth = 0.5 metres.

Calculate the estimated number of Daphnia in the pond.

Use your answer from Question 07.4.

Give your answer in standard form.

Rainfall can cause fertiliser to be washed from farmland into a pond.

The students investigated the effect of fertiliser on the population of Daphnia in water from the pond.

• The students put 20 Daphnia in each of five different concentrations of fertiliser.

• The students counted the total number of Daphnia in each concentration of fertiliser after 2 weeks.

Figure 15 shows the results.

A concentration of 5.0 mg/dm³ of fertiliser caused a large increase in the population of Daphnia.

Explain why.

Figure 14 is repeated below.

The population of Hydra will decrease when 20 mg/dm³ of fertiliser is added to the pond.

Explain why.

Genetic material is made of DNA.

Which structures in the nucleus of a human cell contain DNA?

Figure 16 shows part of one strand of a DNA molecule.

Label parts X, Y and Z on Figure 16.

Choose answers from the box.

A complete DNA molecule is made of two strands twisted around each other.

What scientific term describes this structure?

DNA codes for the production of proteins.

A protein molecule is a long chain of amino acids.

How many amino acids could be coded for by the piece of DNA shown in Figure 16 ?

Tick (✓) one box.

Scientists have now studied the whole human genome.

Give two benefits of understanding the human genome.

Phototropism is a growth response by part of a plant to light.

Name one other tropism.

Give the stimulus the plant responds to in the tropism you have named.

Plan an investigation to show the effect of light from one direction on the growth of plant seedlings.

Include details of any controls needed.

You may use some of the equipment shown in Figure 17 and any other laboratory apparatus.

Explain how phototropism in a plant shoot helps the plant to survive.