AQA GCSE Trilogy Biology Paper 1 Higher June 2023 question paper 8464/B/1H

Communicable and non-communicable diseases are major causes of ill health.

Which disease is a non-communicable disease?

Tick (✓) one box.

Obesity is a risk factor for many non-communicable diseases.

Give one non-communicable disease that obesity is a risk factor for.

Do not refer to the diseases given in Question 01.1 in your answer.

National policies are used to help people who are obese to lose weight.

One national policy is to reduce the amount of sugar added to food and drinks.

Suggest one other national policy that could help people to lose weight.

Body mass index (BMI) is one measure of obesity.

BMI is calculated using the equation:

Table 1 shows how BMI is used to describe an adult’s BMI category.

A person is 1.64 m tall and has a mass of 69 kg.

Determine the BMI category for this person.

Use the BMI equation and Table 1.

The person’s BMI category is

Scientists investigated the effect of smoking and of BMI on the birth mass of babies.

Women’s BMI categories were determined before the women became pregnant.

Suggest why BMI categories were determined before the women became pregnant.

Figure 1 shows the results.

Give two conclusions that can be made from Figure 1.

Measles is a communicable disease.

A virus causes measles.

Describe how the measles virus is transferred from person to person.

Athlete’s foot is a communicable disease.

A fungus causes athlete’s foot.

The athlete’s foot fungus infects the skin on feet.

Scientists estimate that 17% of the UK population have athlete’s foot.

The estimated UK population is 67 961 900

Calculate how many people are estimated to have athlete’s foot.

Athlete’s foot fungus grows in moist conditions.

Suggest one way a person could reduce their chance of catching athlete’s foot.

Figure 2 shows onion cells viewed using a light microscope.

Figure 3 shows the apparatus given to a student.

Describe how the student could use the apparatus to estimate the mean length of

onion cells on the slide.

The circulatory system includes the heart, blood vessels and blood.

The heart pumps the blood in a double circulatory system.

Describe what is meant by a ‘double circulatory system’.

Heart rate is controlled by a group of cells that act as a pacemaker.

Where in the heart is the pacemaker found?

Which blood vessel carries deoxygenated blood?

Tick (✓) one box.

The structure of a vein is different from the structure of an artery.

One difference is that veins have valves but arteries do not have valves.

Explain why veins have valves, but arteries do not.

Describe two structural differences between a vein and an artery.

Do not refer to valves in your answer.

A leaf is a plant organ.

Figure 4 shows tissues in a leaf.

Which tissue is the epidermis?

Tick (✓) one box.

Explain how the spongy mesophyll is adapted for its function.

Use Figure 4.

The xylem is adapted to transport water through a plant.

Explain one way that xylem is adapted for its function.

Figure 5 shows a pair of guard cells around a stoma.

During the day, glucose is made in the guard cells.

Describe how an increase in glucose concentration in the guard cells causes the stoma to open.

Light intensity varies during 24 hours.

Figure 6 shows the overall exchange of carbon dioxide and oxygen for a tree at three different light intensities.

Explain the overall exchange of carbon dioxide and oxygen at the three different light intensities.

Amylase is an enzyme that digests starch in the digestive system.

Explain why starch has to be digested.

A student used a colorimeter to investigate the rate of starch digestion.

A colorimeter measures the percentage of light passing through a liquid.

The darker the colour of the liquid, the less light passes through.

The student:

• mixed 1 cm³ of starch suspension with 10 cm³ of iodine solution

• measured the percentage of light passing through the mixture

• repeated with different concentrations of starch suspension.

Figure 7 shows the results.

Suggest what liquid was used for the test with 0 g/dm³ starch concentration.

Explain the change in the percentage of light passing through the different concentrations of starch suspension in iodine solution.

Use Figure 7.

Question 6 continues on page 21

The student then investigated the rate of starch digestion using amylase.

This is the method used.

1. Put 10 cm³ of starch suspension into a test tube.

2. Put 5 cm³ of amylase solution into a separate test tube.

3. Put both test tubes into a water bath at 37 °C for 10 minutes.

4. Mix the contents of both test tubes together in a beaker.

5. Put the beaker into the water bath.

6. Remove 1 cm³ of the mixture and add it to 10 cm³ of iodine solution.

7. Measure the percentage of light passing through the liquid.

8. Repeat steps 6 and 7 every minute for 5 minutes.

The starch suspension and the amylase solution were kept in the water bath for 10 minutes before being mixed together.

Give the reason why.

Figure 8 shows the results.

The concentration of starch at 3 minutes was 0.3 g/dm³.

Calculate the mean rate of starch digestion for the first 3 minutes.

Use Figure 7 on page 18 and Figure 8 on page 22.

The investigation was carried out at pH 7

Explain how the results would be different if the investigation was carried out at pH 1

Use Figure 8.

Antibiotics are drugs used to treat bacterial infections.

Mutations in bacteria produce new strains.

Some strains of bacteria are resistant to antibiotics.

Where do mutations happen in a bacterial cell?

A scientist investigated which antibiotics (A, B, C, D and E) killed Staphylococcus aureus (S. aureus) bacteria.

This is the method used.

1. Grow S. aureus bacteria in a Petri dish.

2. Cut five small discs of paper.

3. Soak each paper disc in a different antibiotic solution.

4. Put the five paper discs into the Petri dish.

5. Keep the Petri dish at 37 °C for 24 hours.

Figure 9 shows the results.

A clear area around a disc shows where the bacteria have been killed.

The scientist concluded:

‘ S. aureus is resistant to antibiotics C and E ’.

Explain the evidence for this conclusion.

Use Figure 9.

The scientist later discovered that S. aureus is not resistant to antibiotic E.

Suggest how the method was developed and showed that S. aureus is not resistant to antibiotic E.

Broken bones are sometimes repaired using a metal implant.

The area around an implant can become infected with S. aureus bacteria. The infection is usually treated with a long-term course of antibiotics.

Long-term use of antibiotics has led to the development of antibiotic resistant bacteria. Research is being carried out into alternative treatments.

Stem cells from bone marrow and from fat tissue have antimicrobial properties.

A scientist investigated the effect of four treatments on the area of infection around metal implants. Each treatment was injected into the area around the implant.

The four treatments were:

• unreactive solution

• antibiotic solution

• stem cells from fat tissue

• stem cells from fat tissue containing antibiotic.

Each treatment was tested on 5 patients where an infection had developed around their metal implant.

After 7 days of treatment, the scientist calculated the ratio:

area of infection: total tissue area

What was the independent variable in this investigation?

Tick (✓) one box.

Suggest one advantage of using stem cells from fat tissue, rather than using stem cells from bone marrow.

Stem cells containing antibiotic were produced by growing the cells for 24 hours in a solution containing the antibiotic.

How did the antibiotic enter the stem cells from the solution?

Give a reason for your answer.

Tick (✓) one box.

Figure 10 shows the results.

What is the range of results for the treatment with stem cells only?

A student looked at the results and concluded:

‘Injections of stem cells containing antibiotic should be used to treat all implant-related infections’.

Evaluate the student’s conclusion.

Use Figure 10.