Set B (AQA GCSE Biology): Exam Questions

Which of the following options is not a non-specific defence against pathogens?

Figure 1 shows the process of phagocytosis. 

Figure 1

Describe the stages of phagocytosis shown in the image. 

Table 1 shows how the number of white blood cells in the blood changes before and during an infection with a pathogen. 

Table 1

Calculate the difference in the number of white blood cells per dm³ of blood before and during an infection. 

State two roles of white blood cells during an infection other than phagocytosis.

Higher Tier Only

Monoclonal antibodies can be used to determine blood hormone levels.

Pregnancy test strips use monoclonal antibodies.

The hormone HCG is produced in the placenta in pregnant women.

The kidneys excrete HCG.

Figure 1 shows three pregnancy test strips.

Figure 1

Which test strip would belong to a woman who is not pregnant?

Higher Tier Only

Pregnancy testing uses monoclonal antibodies.

Give two other uses of monoclonal antibodies. 

Higher Tier Only

Figure 2 shows the parts of a pregnancy test strip.

Figure 2

If there is no HCG in a woman's urine, she would see a negative test result.

Explain how the pregnancy test strip works to display a negative result. 

Describe and explain the changes that occur in the body during exercise.

A group of athletes carried out a 9-month training programme.

Figure 1 shows the effect of the same type and amount of exercise on one of the athlete’s heart rate before and after the training programme.

Figure 1

Calculate the percentage change in the athletes heart rate 10 minutes after the start of exercise.

Show your working.

The volume of blood pumped out of the left side of the heart in one beat is the stroke volume.

Figure 2 shows the relationship between the athlete's stroke volume and heart rate in beats per minute both before and after completing the training programme.

Figure 2

The cardiac output of the heart can be calculated by:

cardiac output = heart rate × stroke volume

Calculate the difference in cardiac output of the athlete 20 minutes after the start of exercise before and after the training programme. 

Show clearly how you calculated your answer.

Figure 1 shows that the heart of the athlete after completing the training programme beats more slowly than before the training programme.

Use information from Figure 2 to explain why.

Explain how an increased cardiac output helps the athlete to maximise their performance.

Higher Tier Only

Complete Table 1 to show the correct size conversions. Record your answers as ordinary numbers.

Table 1

Higher Tier Only

The mass of bacterial cells was measured in femtograms (fg).

1 femtogram = 1 x 10^-15g

Figure 5

Calculate the mass of bacteria, in grams, immediately after binary fission when the cell growth rate was 0.1 fg s^-1.

Give your answer in standard form.

The electron micrograph shows some cellular structure in a leaf. A student uses their ruler to measure the scale bar, which they find to be 1.5 cm.

Figure 6

Calculate the magnification of the image.

A group of scientists investigated the rates of absorption of different sugars using two pieces of the intestine.

One piece of the intestine was poisoned with cyanide which stops cellular respiration.

The results are shown in Table 3 below.

Table 3

Which of the sugars in Table 3 are absorbed by active transport?

Explain why you chose these sugars, using evidence from Table 3.

One of the scientists states ‘All four of the sugars we investigated can be absorbed by diffusion.

Determine whether the statement is correct or incorrect. Justify your answer.

One of the sugars absorbed by active transport is glucose.

Xylose is a sugar that is the same size as glucose, but it is not absorbed by active transport.

Suggest a reason why.

The wall of the small intestine contains smooth muscle cells.

Muscle cells convert soluble glucose into glycogen which is insoluble in water.

Suggest an explanation as to why it is essential that muscle cells store glucose as glycogen.

An investigation was carried out to test the effect of temperature on the rate of photosynthesis of pondweed.

The volume of oxygen produced per hour was measured. The results can be seen in Table 1.

Table 1

Calculate the mean rate of photosynthesis per hour when the temperature was 45 °C.

Plot the results from Table 1 onto an appropriate graph using the graph paper in Figure 2.

Figure 2

Describe and explain the results shown in the graph.

Higher Tier Only

A farmer growing strawberries in his greenhouse used the results in Table 1 to decide on the best temperature for his greenhouse. He decided to heat the greenhouse to 30 °C.

When the farmer measured the rate of photosynthesis of his plants, he found the rate to be 11.5% slower than the data suggested.

Calculate the rate of photosynthesis that the farmer actually achieved at 30 °C.

Higher Tier Only

Suggest why the farmer may not have achieved a rate of photosynthesis as high as the data in Figure 2 predicted.

The Human Immunodeficiency Virus (HIV) is a virus which emerged during the 1980s and has since infected millions of people globally. 

Explain why HIV sufferers may have an increased chance of suffering from communicable diseases.

Figure 3 shows the percentage of the population with type 2 diabetes and the mean body mass of the population, from 1990 to 2000.

Figure 3

Explain why the study chose to focus on body mass index.

Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis which can be spread through inhaling tiny droplets from the coughs or sneezes of an infected person.

Most infections can be latent and show no sign of disease, but around 10% of infections can progress to an active form of the disease which can be fatal if left untreated.

Table 1 shows the number of new cases of TB and the number of deaths in selected countries.

Table 1

Calculate the case fatality rate for Ethiopia.

Suggest why the number of new cases of TB (as shown in Table 1) is higher in some countries than others.

Multiple sclerosis (MS) is a condition which affects the central nervous system caused by the immune system mistakenly attacking the brain and nerves. MS can lead to symptoms which flare up periodically, such as fatigue, vision problems, muscle spasms, mobility problems, difficulty in thinking, learning or planning, amongst others.

There are several different treatments for MS; two are considered here.

1. Stem cell treatments:  Healthy cells found in the patients bone marrow can be used to rebuild the immune system. Must be used in combination with chemotherapy to remove the harmful immune cells.

2. Disease modifying therapies (DMT): Medicines that can reduce the number of relapses a patient suffers and reduce the symptoms of MS. An example of a DMT is a drug called Lemtrada.

Table 1 gives some extra information about these two treatments for MS.

Table 1

Evaluate the use of stem cells and disease modifying therapies to treat multiple sclerosis.

Heart attacks may be caused if a coronary artery becomes blocked and the flow of oxygenated blood is restricted. This can result in damage to the heart muscle tissue.

Suggest how embryonic cells could be used to treat a patient after a heart attack.

A patient who has suffered a heart attack was offered treatment using stem cells from an embryo, but refused due to the use of embryonic stem cells.

Suggest a reason for this decision.

The patient mentioned in part (c) was offered treatment using their own healthy stem cells removed from their heart tissue.

Evaluate the decision to use these stem cells as an alternative to embryonic stem cells in the treatment of the damaged heart tissue.