AQA GCSE Biology Paper 1 Higher June 2025 question paper 8461/1H

Measles is an infectious disease caused by a pathogen.

What type of pathogen causes measles?

Give one way measles is spread from one person to another person.

One symptom of measles is pain.

In adults, aspirin can be used to treat the pain.

Which plant did aspirin originate from?

Give one other symptom of measles.

Do not refer to pain in your answer.

The spread of measles can be reduced by vaccination.

Explain why vaccinating large numbers of children helps to reduce the spread of the measles pathogen in the population.

Figure 1 shows information about the severity of measles infection in vaccinated and unvaccinated children.

There were 240 children in the survey.

Calculate how many unvaccinated children had a severe measles infection.

Use Figure 1.

It is recommended that all children are given a measles vaccination.

Give evidence from Figure 1 to support the recommendation.

Include data from Figure 1 in your answer.

Eating too much carbohydrate can cause obesity.

Name one disease that obesity is a risk factor for.

Table 1 shows information about sugar intake and obesity in different countries.

Complete Figure 2.

You should:

• label the y-axis

• add the scale for the y-axis

• plot the data for countries C, D, E, F and G from Table 1

• draw a line of best fit.

Countries A and B have been completed for you.

Figure 3 shows information about the relationship between sugar intake and tooth decay.

Name the type of graph shown in Figure 3.

What relationship is shown between the two variables in Figure 3 ?

Tick () one box.

Sugars and starch are carbohydrates.

A student investigated the effect of temperature on the activity of amylase.

For each temperature, the student:

• mixed starch and amylase together

• added iodine solution after 5 minutes.

The iodine solution was yellow-brown before it was added to the mixture.

Table 2 shows the results.

Explain the results at 30 °C and at 90 °C.

How could the student change the investigation to find a more precise temperature that amylase works best at?

Tick () one box.

Protease enzymes are involved in protein digestion.

Different types of protease enzyme are active in different organs of the digestive system.

Complete Table 3 to identify the organ where each protease enzyme is active.

A student investigated osmosis in pieces of potato.

This is the method used.

1. Cut a piece of potato into a cube.

2. Record the mass of the cube.

3. Place the cube into a beaker containing 0.4 mol/dm³ salt solution.

4. After some time, remove the cube and record the mass.

5. Calculate the change in the mass of the cube.

6. Repeat steps 1 to 5 using two more different concentrations of salt solution.

Evaluate the student’s method.

You should include how the student could improve the validity of their results.

Why would a potato cube placed into distilled water increase in mass?

Tick () one box.

Active transport is another process used by potato cells.

Give one way active transport is different from osmosis.

A student investigated the effect of temperature on the rate of photosynthesis in pondweed.

Figure 4 shows how the student set up the apparatus.

This is the method used.

1. Prepare five tubes of pondweed as shown in Figure 4.

2. Place one tube into each of five water baths set at different temperatures.

3. Wait two minutes.

4. Measure the time taken for each piece of pondweed to release 10 bubbles.

What is the independent variable in the investigation?

Table 4 shows the results.

Calculate the rate of photosynthesis at 20 °C.

Give your answer to 3 significant figures.

Give the unit.

Explain the difference in the rate of photosynthesis at 40 °C compared with the rate of photosynthesis at 10 °C.

Give two other factors that affect the rate of photosynthesis.

Do not refer to temperature in your answer.

Describe one way the method could be changed to obtain more accurate results for the rate of photosynthesis.

A gardener noticed that some plants were not growing as well as usual.

Describe two ways the gardener could identify a plant disease.

One of the plants had purple spots on its leaves and the leaves fell off.

What disease is the plant most likely to have?

A different plant had yellow leaves, but no spots.

Explain why plants may develop yellow leaves.

This question is about the human circulatory system.

Blood plasma transports blood cells around the body.

Give one other function of blood plasma.

Do not refer to oxygen in your answer.

Figure 5 shows a red blood cell.

The image of the red blood cell in Figure 5 is magnified 7200 times.

Calculate the real diameter of the red blood cell.

Give your answer in micrometres (µm).

Figure 6 shows the heart.

Blood pressure is a measure of the force of the blood against the walls of the blood vessels.

Table 5 shows information about the different types of blood vessel shown in Figure 6.

Complete Table 5 using the correct letters from Figure 6.

One row has been completed for you.

Name blood vessel D in Figure 6.

Describe the structure of the walls of an artery.

An athlete ran on a running machine.

The athlete:

• reached their maximum intensity of exercise and then stopped exercising

• had their use of oxygen recorded

• had the lactic acid concentration in their blood recorded.

During the exercise the athlete respired aerobically and anaerobically.

Explain why anaerobic respiration is less efficient than aerobic respiration.

Figure 7 shows the athlete’s use of oxygen and the lactic acid concentration of blood during exercise and after exercise.

Explain why the use of oxygen remained high after the athlete stopped exercising.

Some athletes regularly exercise in conditions that increase the number of red blood cells.

Explain why having an increased number of red blood cells is an advantage to an athlete.

Diffusion is important for gas exchange.

Define the term ‘diffusion’.

Fish exchange gases through gills.

Oxygen from the water enters the blood of a fish through the gills.

Figure 8 shows part of a gill.

Explain how gills are adapted to maximise the exchange of oxygen between the water and the blood.

Some fish rest on the sea floor.

Explain why the metabolic rate of a fish is higher when swimming compared with when resting.

In people with severe liver disease the liver stops working correctly.

A person with severe liver disease can be treated with:

• an injection of embryonic stem cells or

• a liver transplant from a donor.

The person’s body can reject embryonic stem cells and can reject a liver transplanted from a donor.

What property of embryonic stem cells makes them suitable to treat liver disease?

Suggest one ethical reason why a person may not want an injection of embryonic stem cells.

Drugs can be used to reduce the risk of liver rejection after a transplant.

One drug contains monoclonal antibodies.

The monoclonal antibodies are specific to an antigen on the surface of liver cells.

Figure 9 shows part of the process used to create the monoclonal antibodies.

Name the three types of cell in Figure 9.

How is the mouse stimulated to produce cell type A ?

A patient with severe liver disease was given a liver transplant.

The drug containing the monoclonal antibody is given to the patient.

Explain how the monoclonal antibody stops the patient’s white blood cells from attacking the cells of the donor liver.

Give one other use of monoclonal antibodies.

Do not refer to pregnancy tests.

The liver produces bile.

Bile is needed for efficient digestion.

Where is bile stored in the human body?

Tick () one box.

Explain why a person with severe liver disease has difficulty digesting fats.

Figure 10 shows a bacterial cell and a yeast cell.

Which statement about bacterial cells and yeast cells is correct?

Tick () one box.

Give two features of a yeast cell that are not found in a bacterial cell.

Use Figure 10.

A scientist investigated the effect of different antibiotics on one type of bacterium.

The scientist:

• used three samples of culture medium

• added a different antibiotic to each sample

• added equal numbers of bacteria to each sample.

Figure 11 shows the results.

Compare the effectiveness of the antibiotics shown in Figure 11.

It was not possible for the scientist to count the total number of bacteria per cm³ of culture medium.

The cells were too close together to be counted accurately.

The scientist took 10 samples from the culture medium. Each sample had a volume of 0.02 cm³.

Describe how the scientist could use the samples to estimate the number of bacteria