AQA GCSE Trilogy Biology Paper 1 Higher June 2022 question paper 8464/B/1H

Bacteria can cause a variety of diseases in humans.

What are two similarities between a bacterial cell and an animal cell? Tick (✓) two boxes.

Salmonella food poisoning is caused by bacteria in food. Give one symptom of salmonella food poisoning. Do not refer to vomiting or diarrhoea in your answer.

What is the name of the first antibiotic developed?

A child with a severe bacterial infection was given a course of antibiotics.

Figure 1 shows how the concentration of live bacteria in the child’s body changed when taking the course of antibiotics.

The concentration of live bacteria in the body continued to increase after starting the course of antibiotics. Suggest one reason why.

After 3 days of taking the antibiotic:

• the child felt better

• there were still bacteria in the child’s body.

Why did the child feel better? Tick (✓) one box.

Suggest why doctors do not give antibiotics to patients with minor infections.

Figure 2 shows blood viewed using a microscope.

A vaccine will stimulate the production of antibodies. Which part of the blood in Figure 2 produces antibodies? Tick (✓) one box.

Which part of the blood in Figure 2 starts the clotting process? Tick (✓) one box.

This question is about cell division.

Write the biological structures from the box in the correct order of size.

Figure 3 shows how a fertilised egg cell can produce specialised cells.

Name Process A.

How many cell divisions are needed to form a 16-cell embryo from the original fertilised egg cell?

In humans a fertilised egg cell contains 23 pairs of chromosomes. How many chromosomes will there be in each of the embryo cells?

Figure 4 represents a cell cycle for a human embryonic cell.

Describe one change in the cell that occurs during each of the stages of the cell cycle.

Cell division is important in the growth of multicellular organisms.

Figure 5 shows the mean height of boys and of girls from birth to age 18 years.

Compare the growth of boys with the growth of girls. Use data from Figure 5 in your answer.

Give one way that cell division by mitosis is important in fully grown animals.

Amylase is an enzyme that digests starch.

Which organs in the human digestive system produce amylase? Tick (✓) one box.

A student investigated the effect of pH on the activity of amylase. This is the method used.

1. Prepare amylase solution at pH 5

2. Mix the amylase solution with starch in a boiling tube.

3. Remove a drop of the amylase-starch mixture every 30 seconds and test it for the presence of starch.

4. Record the time when all the starch has been digested.

5. Repeat steps 1 to 4 using amylase solution prepared at pH 6, then at pH 7 and

then at pH 8

What was the independent variable in this investigation?

Describe how the student would know when all the starch had been digested.

Figure 6 shows the student’s results.

What was the optimum pH for the amylase? Use Figure 6.

A scientist did a different investigation. This is the method used.

1. Prepare amylase solution at the optimum pH.

2. Mix the amylase solution with starch in a boiling tube.

3. Measure the concentration of sugar every 10 seconds for 2 minutes.

Figure 7 shows the scientist’s results.

How much time did it take for the amylase to digest all the starch? Use Figure 7.

Determine the rate of sugar production per minute at 40 seconds.

Explain how the structure of enzyme molecules is related to the effect of pH on the activity of amylase.

Photosynthesis is an important chemical reaction in plants.

Why is light needed for photosynthesis?

What is the equation for photosynthesis? Tick (✓) one box.

A student investigated the effect of different colours of light on the rate of photosynthesis at room temperature. The student used pondweed in water. A piece of pondweed was placed in red light, then in blue light and then in green light. Each colour of light was the same intensity. Describe how the student should make accurate measurements to obtain valid results for the rate of photosynthesis.

A scientist investigated the effect of different wavelengths of light on the rate of photosynthesis. The wavelength of light determines the colour of the light. Figure 8 shows the student’s results. Figure 9 shows the scientist’s results.

Why are the results for the two investigations presented differently?

Suggest the range in wavelength of green light. Use Figure 8 and Figure 9.

This question is about tumours.

Describe the similarities and differences between benign tumours and malignant tumours.

Figure 10 shows data about skin cancer in males and females for different age groups in the UK. It shows:

• the number of new cases of skin cancer in 1 year

• the number of people with skin cancer per 100 000 population in 1 year.

There are no new cases of skin cancer diagnosed in people younger than 15 years of age. Explain why.

Give two conclusions about the number of new cases of skin cancer. Use Figure 10.

The data for the number of people with skin cancer is given per 100 000 population. Suggest why the data is not given as the total number of people.

Figure 10 is repeated below.

Describe two trends shown in Figure 10. Use only the data for the number of people with skin cancer per 100 000 population.

The estimated population of males aged 80 to 84 years was 694 000 Calculate the number of males aged 80 to 84 years with skin cancer in that year. Use Figure 10. Give your answer to 3 significant figures.

This question is about the heart.

Why is the heart described as an organ?

Valves in the heart keep the blood flowing through the heart in one direction. Figure 11 shows the heart with one of the valves labelled.

Explain the effects on a person if the valve labelled in Figure 11 developed a leak.

Faulty heart valves can be replaced using biological or mechanical valves. The faulty valve is replaced during an operation. Biological valves:

• are from animals or human donors

• allow blood to flow through them normally

• wear out and stiffen over time, so may need to be replaced.

Mechanical valves:

• are made from synthetic materials

• may cause blood clots on the surface of the valve

• require anti-clotting drugs to be taken for the rest of the patient’s life

• can last for a very long time in ideal conditions.

A young woman enjoys extreme sports and would like to start a family. The woman needs a heart valve replacing.

Describe the advantages and disadvantages for this young woman of having a biological heart valve instead of a mechanical heart valve.