AQA GCSE Biology Paper 2 Foundation November 2021 question paper 8461/2F

The theory of evolution states that organisms alive today evolved by natural selection from other species that are now extinct.

Which two scientists proposed the theory of evolution by natural selection?

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Fossils provide evidence for evolution. Figure 1 shows a fossil footprint of a dinosaur.

What is a fossil?

How was the fossil in Figure 1 formed?

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Dinosaurs are extinct. Give two causes of extinction.

Which two of the following provide evidence for evolution?

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Many internal processes of the human body are controlled by hormones. Hormones are produced by glands. Figure 2 shows glands in a woman’s body.

Which gland is the pituitary gland?

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Which gland is the pancreas?

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The hormone insulin helps to decrease the blood glucose concentration. Insulin causes its target organs to take in glucose from the blood.

Which of the following is a target organ for insulin?

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The glucose is stored as an insoluble substance. What is the insoluble storage substance that is formed from glucose?

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Scientists investigated the effect of a glucose drink on the concentration of glucose in

a person’s blood. This is the method used.

1. Take a small sample of blood from the person.

2. Measure the concentration of glucose in the person’s blood.

3. Give the person a drink containing 50 grams of glucose.

4. Measure the concentration of glucose in the person’s blood at intervals.

5. Calculate the change in blood glucose concentration from the starting value.

Figure 3 shows the results.

Figure 3 shows the change in blood glucose concentration.

At the start of the investigation, the blood glucose concentration was 5 mmol/dm³. Calculate the highest blood glucose concentration during the investigation. Use information from Figure 3 in your answer.

What is the time taken for the blood glucose concentration to decrease from its highest value back to the starting value? Use data from Figure 3 in your answer.

Why can you not be certain that your answer to Question 02.6 is accurate?

Figure 3 shows the results for a person who does not have Type 2 diabetes. Sketch a line on Figure 3 to show the results you would expect for a person who has

People eat fish caught in the North Sea. Figure 4 shows a food chain.

The algae make glucose by photosynthesis. Which two substances do the algae need for photosynthesis?

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What is the source of energy for photosynthesis?

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Which pyramid of biomass is correct for the food chain shown in Figure 4 ?

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Figure 5 shows the biomass of adult herring in the North Sea between

1950 and 1990.

Too many herring were caught in the 1960s. Calculate the percentage decrease in the biomass of adult herring between 1960 and 1970. Use the equation:

Give your answer to the nearest whole number.

From 1977, laws were introduced to help conserve herring.

Describe the change in biomass of adult herring from 1977 to 1990. Use data from Figure 5 in your answer.

One of the laws was to control mesh size of fishing nets. Figure 6 shows a fishing net with a legal mesh size.

Herring can live for up to 12 years. Herring start to reproduce when they are 3 to 4 years old. Explain how the control of mesh size of fishing nets has helped to conserve stocks of herring.

The human eye can form images of objects that are at different distances away from the eye. Figure 7 is a diagram of the eye.

Label structures A, B and C on Figure 7.

Choose answers from the box.

The eye in Figure 7 is focused on a distant object.

If the eye then focuses on the words in a book, changes would occur in the eye. The light rays would be refracted more by the lens.

How does the lens refract the light more?

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Which two structures control the shape of the lens?

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To form a clear image, the light rays entering the eye must focus on one structure in the eye. Name the structure.

An insect flies near a person’s eye. The person blinks. This is a reflex action. Figure 8 shows the coordination system for this reflex action.

Complete Figure 8.

Choose answers from the box below. Write one word in each of boxes 2, 3 and 4 of Figure 8.

Potato blight is a disease of potato plants. Potato blight is caused by the fungus Phytophthora infestans.

What is the genus of the fungus that causes potato blight?

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The fungus grows near the surface of the potato. How does growing near the surface help the fungus to respire?

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A farmer sprays his potato plants with a pesticide.

The pesticide kills the fungus that causes potato blight. Spraying the crop with a pesticide could decrease biodiversity in a river flowing through his farm.

What does ‘biodiversity in a river’ mean?

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The farmer sprayed pesticide on his potato plants. The next day it rained heavily. Explain why the biodiversity in the river decreased.

Another method of preventing potato blight is to breed potatoes that are resistant to blight. Resistance to potato blight is controlled by two alleles: R = a dominant allele for having resistance to blight. r = a recessive allele for not having resistance to blight. A scientist crosses two potato plants. Each plant has the genotype Rr.

Complete Figure 9 to show the possible genotypes of the offspring produced.

Draw a ring around one of the homozygous genotypes in Figure 9.

What percentage of the offspring in Figure 9 will be resistant to potato blight?

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Potatoes can also reproduce asexually. Potatoes from one plant can be planted in the ground to produce new potato plants. All the new plants from a parent plant that is resistant to blight will also be resistant to blight. Explain why.

A student estimated the percentage cover of buttercup plants in a field. The student used a quadrat. The quadrat was divided into 25 equal squares. Figure 10 shows the quadrat.

This is the method used.

1. Place the quadrat on the ground.

2. Record how many squares in the quadrat contain buttercup plants.

3. Place the quadrat in a new position in the field.

4. Record how many squares in the quadrat contain buttercup plants.

5. Repeat steps 3 and 4 another three times.

What method should the student have used for placing the quadrat?

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The student calculated the percentage cover of buttercup plants for each quadrat. Table 1 shows the student’s results.

Calculate mean value X in Table 1.

Table 1 shows that quadrat 1 and quadrat 5 each had 40% cover of buttercup plants.

Figure 11 shows the results for quadrat 1 and quadrat 5.

The student’s method of estimating the percentage cover of buttercup plants is not accurate. How does Figure 11 show this?

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The student wanted to get a more valid estimate of the percentage cover of buttercup plants in the field. Suggest two improvements to the method to make the results more valid.

Give three environmental factors that would affect the growth of buttercup plants in a field.

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Scientists are very concerned about the changes in concentration of carbon dioxide in the Earth’s atmosphere. Figure 12 shows the concentration of carbon dioxide in the atmosphere between 1988 and 2014.

Describe two patterns shown in Figure 12. Use data from Figure 12 in your answer.

Give two human activities that affect the concentration of carbon dioxide in the atmosphere.

The trend shown in Figure 12 may continue for many years. Explain what effect the changing concentration of carbon dioxide in the atmosphere could have on living organisms.

The nucleus of a cell contains DNA.

Name the structures inside the cell nucleus that contain DNA.

Figure 13 shows part of a DNA molecule.

Name the part of the DNA molecule labelled X.

What type of substances are labelled A, C, G and T in Figure 13 ?

Figure 14 shows another section of a DNA molecule.

Four of the substances you named in Question 08.3 are not labelled in part Y of Figure 14. Label each of these substances with the correct letter, A, C, G or T. Use information from other parts of Figure 14 to help you.

What is happening to the DNA in part Z of Figure 14 ?

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A gene is a length of DNA. What type of substance does a gene code for?

Most human body cells contain 6 10^–12 grams of DNA. What mass of DNA will a human sperm cell contain?

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What is the name of the type of cell division that produces sperm cells?

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A student investigated the effect of temperature on the decay of milk. Figure 15 shows the apparatus the student used.

This is the method used.

1. Set up the apparatus as shown in Figure 15 with the milk at 20 C.

2. Record the pH over 5 days using the computer.

3. Repeat with another batch of fresh milk at 25 C.

How could the student keep the milk at a constant temperature for 5 days?

Give one variable the student should keep constant. Do not refer to temperature in your answer.

Table 2 shows the student’s results for the milk at 20 C.

Complete Figure 16.

You should:

• label the x-axis

• use a suitable scale for the x-axis

• plot the data from Table 2

• draw a line of best fit.

The data you plotted in Question 09.3 were obtained at 20 C. Sketch a line on Figure 16 to show the results you would expect at 25 C.

Human body temperature is controlled within very narrow limits. Scientists investigated the effect of drinking ice-cold water on:

• internal body temperature

• the rate of sweating.

This is the method used.

1. Sit a person inside a room kept at a constant temperature of 25 C.

2. Measure the person’s internal body temperature near the brain.

3. Measure the person’s rate of sweating.

4. After 20 minutes, give the person 500 cm³ of ice-cold water to drink.

5. Continue to measure the person’s internal body temperature and sweating rate for a further 50 minutes.

Give the reason why the person should not move during the investigation.

Figure 17 and Figure 18 show the scientists’ results.

What is this person’s normal internal body temperature?

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The results show that when the ice-cold water was drunk, the temperature near the brain decreased.

Explain why the temperature near the brain decreased.

The thermoregulatory centre in the brain responds to the decrease in temperature. How does the thermoregulatory centre send information to sweat glands in the skin?

The rate of sweating changes between 24 minutes and 36 minutes. Explain how this change helps to maintain the person’s normal body temperature.

During exercise, the skin appears red. What causes the skin to appear red?

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Decay occurs in a compost heap. Figure 19 shows a compost heap.

Describe:

• how microorganisms in the layers of soil help to recycle chemicals in the dead plants

• how the chemicals are used again by living plants.