AQA Past Papers Practice

Yeast cells can respire anaerobically.
0 1 . 3 Complete the word equation for anaerobic respiration in yeast.
Choose the answer (ethanol, glycerol, starch, urea.)

glucose → ………….. + carbon dioxide

Tardigrades can survive in extremely cold and dry conditions.
In extreme conditions, tardigrades have the following adaptations:
1. Produce a waxy layer to cover their body surface.
2. Curl up into a tiny ball.
3. Are light enough to be carried by the wind.
Describe how each adaptation helps the tardigrade to survive.
You should give a different reason for each adaptation.
Adaptation 1
Adaptation 2
Adaptation 3

Digestive enzymes break down insoluble molecules into smaller, soluble molecules.
Name two insoluble molecules digested by enzymes.
Choose the answers (amino acid, fat, fatty acid, glucose, protein)

This question is about white blood cells and pathogens.
White blood cells have cell membranes.
Describe the function of the cell membrane.

Skin cells contain many ribosomes.
Suggest why ribosomes are not visible in Figure 6.

The number of people who smoke cigarettes has decreased since the 1990s.
Choose reason why

Describe two possible effects that a faulty valve can have on the functioning of the heart.

Tardigrades can reproduce both sexually and asexually.
During asexual reproduction, the female produces offspring from eggs which have not
been fertilised.
Give one advantage to the female if she does not need to find a mate.

Label parts A on Figure 1.

People must be vaccinated with a new vaccine each year to prevent infection from
influenza.
Explain why a new vaccine is used each year.

What does heterozygous mean?

Ebola is a disease caused by a viral pathogen.
The Ebola virus attaches to the cell membranes of some body cells.
The Ebola virus can spread very quickly by direct contact with infected patients or
their body fluids

Choose one other way to reduce the spread of the Ebola virus.

Ebola viruses enter box the cells and reproduce rapidly. The cells then burst and release
many copies of the viruses.
When white blood cells burst they release proteins that block blood flow to the liver.
The liver fails because there is a lack of blood flow.
A failing liver cannot produce sufficient chemicals for blood clotting.
Suggest one symptom a person might have if the blood does not clot.

The size of the stomata can be controlled.
What parts of the leaf control the size of the stomata?

In Mendel’s breeding experiment there were 297 purple flowers and 105 white flowers
in the second generation.
Calculate the actual ratio Mendel achieved.
Give your answer to 3 significant figures.

Ratio of purple flowers : white flowers =?

Mendel published his results in 1866, but his ideas were ignored until the early 1900s.
Suggest one reason why people did not accept Mendel’s ideas in 1866.

Label parts B on Figure 1.

A leaf has many pores called stomata.
Water vapour is lost from a plant by diffusion through the stomata.
At what temperature would most water vapour be lost from a leaf?

What is the main type of tissue found in the wall of the heart?

What does anaerobic mean?

Which specimen in Table 1 would be visible without a microscope?

Give the reason why the volume of the mixture did not increase at 80 °C.

Increased levels of carbon dioxide in the atmosphere contribute to global warming.

Choose two possible effects of global warming.

Structures A, B, C and D are valves.
Which valve opens when the blood pressure in the right ventricle is greater than the
blood pressure in the pulmonary artery?
Write the correct letter

Owls are large birds.
Owls eat mice and small birds.
Which food chain is the most efficient at transferring energy from plants to owls?

A leaf is a plant organ.
Name two other plant organs.