Set A (AQA GCSE Biology): Exam Questions

The intertidal zone is the area along a coast which is underwater at high tide and above water (exposed) when the tide is low.

A group of students on a field trip in Asia wanted to investigate the distribution of two species of seaweed (C. racemosa and C. microphysa) along a rocky shore to establish whether they could live at certain positions. 

Seaweeds are multicellular algae that produce glucose. 

Describe the role that seaweeds play in an ecosystem as producers.

Describe and explain a method that the students could use to investigate the distribution of the two species of seaweed along the rocky shore using a quadrat and a tape measure. 

You should explain how the students would collect valid data.

How could the students alter their method if they wanted to investigate the abundance of each type of seaweed along the coastline by measuring percentage cover?

Another group of students carried out the same investigation the year before.

Their results are shown in Figure 1 below.

Figure 1

Suggest and explain a conclusion that the students could draw from their results using information from Figure 1.

Figure 1 shows a food chain for different organisms living in the sea. This biomass at each trophic level is also shown.

Figure 1

Describe the third trophic level of this food chain.

Draw a pyramid of biomass for the food chain shown in Figure 1 on the graph axis provided in Figure 2.

You should use a suitable scale and ensure that all labels are included.

Figure 2

Calculate the percentage of the biomass transferred from the phytoplankton to the snapper fish.

Give the answer to 2 significant figures.

Give three ways in which biomass can be lost between trophic levels.

Figure 7 shows the path of light entering the front part of the eye of a person with normal vision, whilst looking at a close object.

Figure 7

As people get older (typically 40+), their lenses lose flexibility and can't spring back into a round shape when looking at close objects.

Explain what effect a less flexible lens would have on the path of light. 

Explain the changes that occur in the normal human eye to focus on near and distant objects.

Explain why long-sighted people are unable to focus on near objects and how this can be corrected using glasses.

As people age, their vision tends to deteriorate. The majority of adults choose to wear glasses to correct their vision as shown in Figure 8.

Figure 8

Explain how laser eye surgery can correct a person's eyesight and suggest a reason why it is not as popular as other methods of vision correction.

Describe the effect phototropism has on the growth of plant roots.

In the late 1800s, Charles Darwin performed an experiment where he grew maize seedlings in the dark, in a horizontal orientation. Half of the seedlings had the root tip removed (A), the other half of the seedlings were left intact (B). The results of his investigation are shown in Figure 2.

Figure 2

Explain what these results demonstrate for each experiment.

Figure 3 represents a plant shoot growing, it is illuminated from the side.

Figure 3

Draw an annotated diagram showing accumulation of auxins in response to light and how the shoot tip will grow.

Higher Tier Only

Ecologists carried out a study into the effect of soil moisture level on the distribution of certain species of wildflower in a large meadow.

Figure 3 shows the meadow from the study, bounded by a river to the north and east and by farmland to the west and south.

The meadow slopes down to the river, with the south end of the meadow elevated approximately 10 metres above the north end. 

Figure 3

A quadrat study was carried out to determine the abundance and distribution of wildflowers in the meadow, alongside a measurement of soil moisture levels using a soil moisture probe of the sort shown in Figure 4.

Samples were analysed in four areas of the meadow, W, X, Y and Z as shown in Figure 3.

Figure 4

The data found by the ecologists is shown in Table 1.

Table 1

Suggest reasons for the differing soil moisture levels at W, X, Y and Z.

Higher Tier Only

Using the data in Table 1, determine the correct ranking of the wildflower species listed below, from 1 to 6, in ascending order of adaptation to dry conditions.

Higher Tier Only

Suggest why the answer you gave in part 3(b) may not be the the most accurate rank order of adaptation to dry conditions. 

Identify and explain two structural adaptations of wildflowers that would benefit the plant living in a dry soil environment.

Selective breeding is particularly useful to farmers who want to produce animals with particular characteristics.

Cow X is a cow in a farmer’s herd that has a higher muscle density than normal when fed the same diet.

The farmer wants to produce more cows like Cow X.

Suggest why the farmer wants to do this.

The farmer wants to breed Cow X with a bull (male) that has produced larger calves than normal.

The farmer hopes to have multiple genetically identical offspring.

Describe how this could be achieved.

Potentially, scientists could use cloning techniques to increase the populations of endangered animals and prevent them from becoming extinct.

Evaluate the use of cloning versus conservation to prevent endangered animals from becoming extinct.

Higher Tier Only

The following hormones are involved in the menstrual cycle:

• Follicle stimulating hormone (FSH)

• Luteinising hormone (LH)

• Oestrogen

• Progesterone

Draw an annotated graph showing how the levels of the above hormones change throughout the menstrual cycle.

Higher Tier Only

Suggest how oestrogen functions in both positive and negative feedback within the menstrual cycle.

Figure 3 shows changes in the thickening of the uterus wall lining in two women X and Y.

 Figure 3

Suggest why the thickness of the uterus wall lining is different between the two women.

Higher Tier Only

Explain how the levels of LH and progesterone will differ between the women X and Y during the next calendar month (assume a normal menstrual cycle for woman Y).