AQA GCSE Biology Paper 1 Higher June 2023 question paper 8461/1H

A root is a plant organ. Plant roots contain many different types of tissue.

What is a tissue?

Tissue in the tip of a plant root contains stem cells. Stem cells can differentiate into any type of cell. Name the type of tissue in plants that contains stem cells.

In the past many drugs were extracted from plants.

Aspirin is a painkiller. Which plant does aspirin originate from?

Scientists have extracted chemical A from the deadly nightshade plant. Chemical A can be used as a painkiller. Table 1 shows information about where chemical A is found.

The scientists usually extract chemical A from the berries of the deadly nightshade plant. Suggest one reason why berries are used instead of leaves or roots.

A deadly nightshade plant has chlorosis (yellow leaves).

The mass of chemical A found in the leaves of the plant is 60% of the mass shown in Table 1.

Calculate the mass of chemical A in 200 g of the leaves with chlorosis. Give your answer in mg.

Suggest one reason why the leaves of the deadly nightshade plant have chlorosis.

Chemical A has not been tested in large-scale clinical trials in the UK.

It is important for drugs to be tested in clinical trials before the drugs are approved for use by the public. Give two reasons why.

There are many online reports making claims about the effects of chemical A. Some of these reports are biased.

Suggest one reason why a report making claims about the effects of chemical A may be biased.

How can scientists be sure that claims about new drugs are valid? Tick (✓) one box.

This question is about the circulatory system. Figure 1 shows the human heart.

Which part of the heart receives oxygenated blood from the lungs? Tick (✓) one box.

Which part of the heart pumps deoxygenated blood to the lungs? Tick (✓) one box.

A group of cells called the pacemaker controls the resting heart rate. Where in the heart is the pacemaker found? Tick (✓) one box.

Figure 2 shows a cross section of an artery and of a vein.

Describe two ways that the structure of an artery is different from the structure of a vein.

In coronary heart disease, the coronary arteries become narrower. A build-up of fatty material can cause a blockage in a coronary artery. Table 2 shows how a blockage in a coronary artery affects blood flow.

Describe the trend shown in Table 2.

Complete Figure 3. You should:

• use a suitable scale for the y-axis

• plot the data from Table 2

• draw a line of best fit.

Predict the blood flow in a coronary artery with a 35% blockage. Use Figure 3.

Explain the effect of a partly blocked coronary artery on the human body.

There are different treatments for a blockage in a coronary artery. Explain how one treatment for a blockage in a coronary artery works.

Salmonella bacteria cause outbreaks of food poisoning in humans. To prevent food poisoning in humans, farmers vaccinate their animals against Salmonella bacteria.

How do Salmonella bacteria in food cause the symptoms of vomiting and diarrhoea?

During a food poisoning outbreak, scientists identified the farm where the food came from. The farmer had not vaccinated the farm animals against Salmonella bacteria.

The food poisoning outbreak could have been prevented if the farm animals had been vaccinated. Explain how:

• the immune systems of animals respond to a vaccination

• the immune response in farm animals prevents an outbreak of food poisoning in humans.

Most cases of food poisoning do not need to be treated with antibiotics. However, some patients may need to take antibiotics to recover. Scientists investigated the effectiveness of five different antibiotics on the Salmonella bacteria in the outbreak. Antibiotics A, B, C, D and E were used in the investigation. Figure 4 shows the results.

Describe two aseptic techniques the scientists should have used in the investigation.

The scientists incubated the bacteria at 37 °C. Students in school laboratories incubate bacteria at 25 °C. Explain why scientists use 37 °C but students must use 25 °C to incubate bacteria.

What is the purpose of the paper disc with no antibiotic in Figure 4 ?

The scientists concluded that either antibiotic A or antibiotic B should be prescribed to patients with food poisoning. Why should antibiotic A or antibiotic B be prescribed?

The scientists wanted to be more certain about which antibiotic should be prescribed. Describe how the results in Figure 4 could be used to obtain a quantitative comparison of antibiotics A and B.

One year later, there was another outbreak at the farm involving Salmonella bacteria. Antibiotic B did not have an effect. Suggest why antibiotic B no longer had an effect.

Antibiotics treat food poisoning because they kill Salmonella bacteria inside the human body. Some antibiotics work because they damage the bacterial cell wall. The bacteria die because the cells burst. Explain why the cells burst.

This question is about exercise.

During vigorous exercise, anaerobic respiration occurs in a person’s body. Explain two effects of anaerobic respiration on the person’s body.

Design an investigation to show the effect of different types of exercise on the heart rate of athletes.

Anabolic steroids are drugs. Anabolic steroids:

• increase muscle mass in humans

• are banned in most competitive sports.

Some athletes take anabolic steroids to improve their performance in sport.

Explain how taking anabolic steroids could improve an athlete’s performance.

Scientists use monoclonal antibodies to test for the presence of anabolic steroids in an athlete’s urine. To produce monoclonal antibodies, a mouse lymphocyte is combined with a tumour cell.

What type of cell is created when a mouse lymphocyte and a tumour cell combine? Tick (✓) one box.

Describe how scientists make monoclonal antibodies using the cell created when a mouse lymphocyte and a tumour cell combine.

What property makes a monoclonal antibody useful in detecting the presence of an anabolic steroid in urine? Tick (✓) one box.

Figure 5 shows a test strip that can detect the presence of an anabolic steroid in an athlete’s urine.

The end of the test strip is dipped in urine. The urine moves up through the test strip. The test area and the control area contain a dye. The dye turns blue when monoclonal antibodies bind to it.

Suggest the purpose of the control area in the test strip.

Figure 6 shows the urine test results of four athletes.

Describe the evidence in Figure 6 that shows the test for athlete B has not worked. Suggest one reason why the test did not work.

Which athlete has tested positive for anabolic steroids in their urine? Tick (✓) one box.

The protist that causes malaria is passed from one person to another person by mosquitos.

What term describes an organism that passes a pathogen from one person to another person?

Figure 7 shows the malarial protist.

The malarial protist is a eukaryotic cell. Describe three ways the structure of the malarial protist is different from the structure of a prokaryotic cell. Do not refer to size in your answer.

During one stage of malaria infection, the malarial protists enter red blood cells and cause them to burst. Explain why the bursting of red blood cells causes tiredness.

The malarial protist reproduces sexually and asexually during a life cycle. Complete Table 3 to give three differences between sexual reproduction and asexual reproduction. One difference has been completed for you.

One drug for treating malaria prevents mitosis occurring in the malarial protist. The drug stops the synthesis of new DNA bases in the cell. Suggest how the drug prevents mitosis occurring.

Describe the process of cell division by mitosis.

Different types of disease may interact. Scientists studied the incidence of malaria infections in children:

• with disorder S

• without disorder S.

The incidence of malaria in children with disorder S was calculated as a percentage of the incidence in children without disorder S. Table 4 shows the results.

Describe what the results in Table 4 show about the interaction between disorder S and malaria.

This question is about photosynthesis.

Complete the symbol equation for photosynthesis.

Figure 8 shows how the rate of photosynthesis changes with light intensity.

Which part of the graph could be represented by the equation y = mx + c ? Tick (✓) one box.

A student investigated the effect of colour of light on the rate of photosynthesis

in leaves. Figure 9 shows how the investigation was set up.

Table 5 shows the results.

Give one way the student could change the colour of the light shining on the leaf discs.

Give the independent variable and the dependent variable in this investigation. Independent variable

Dependent variable

All of the air had to be removed from the leaf discs before placing them in the beaker. Suggest one reason why.

The leaf discs were placed in a beaker of sodium hydrogencarbonate

Explain why sodium hydrogencarbonate solution was used instead of water.

Explain why the leaf discs moved to the surface of the solution during the investigation.

There are two types of chlorophyll in leaves.

Figure 10 shows the percentage of different wavelengths of light that the two types of chlorophyll absorb.

Table 6 shows the colour of different wavelengths of light.

Suggest the advantage to a plant of having two types of chlorophyll.

Table 5 is repeated below.

The leaf discs in the investigation are green. Explain the results in Table 5 for blue light and for green light. Use data from Figure 10 and Table 6.