May/June 2022

The diagram depicts a plant cell. The cell has been stained using iodine solution. Once the iodine solution has been applied, what colours would the cell wall and the starch grain be?

Cell structure and function

Four food tests were performed separately on four white powders, A, B, C and D. The table shows the outcomes. Which powder contains a carbohydrate, a fat and a protein?

Biological molecules

Give one example of assimilation.

Absorption and assimilation

Four plant shoots were arranged as shown in the diagram, under identical environmental conditions. Waterproof petroleum jelly was placed on the plant leaf surfaces, as shown. Each beaker, together with its plant shoot and water, was weighed at the beginning of the experiment and again after $24$ hours. After $24$ hours, the percentage loss in mass was worked out for each plant shoot. Which row gives the results of this experiment?

Transpiration and translocation

What is the principal reason that water moves upward to the leaves in xylem vessels?

Transpiration and translocation

Which blood vessels transport blood to the heart and to the lungs?

Blood vessels

The diagram shows the right-hand side of the human heart while the ventricle is relaxed. Which row gives the positions of valve $X$ and valve $Y$ when the ventricle contracts?

Heart

People whose diet is high in fat and who smoke have two major risk factors for which disease?

Disease

Which equation shows aerobic respiration in plant cells?

Aerobic respiration

Four flasks are sterilised and arranged as shown. Which flask will show evidence of fermentation (anaerobic respiration) after one hour?

Anaerobic respiration

Which row shows what happens when humans inhale?

Human gas exchange

The diagram shows the form of a red blood cell. What advantage does this shape provide?

Specialised cells, tissues and organs

Which graph illustrates the change in the concentration of molecules in the dialysis fluid during kidney dialysis?

Urinary system

The diagram illustrates several structures in human skin. Which row gives the names of structures X, Y and Z?

Specialised cells, tissues and organs

The graph illustrates how a person’s body temperature varies with time. What might be responsible for the changes in body temperature during periods 1 and 2?

Temperature control

The diagram depicts a cross-section of the human brain. If structure X is harmed, which body functions could be affected?

Mammalian nervous system

Which diagram illustrates the way light from a distant object is brought to a focus on the retina so that a clear image is formed?

Mammalian sense organs

The graph illustrates how blood glucose concentration changes in one person over 24 hours. Which statement accounts for the graph’s shape?

Blood glucose control

What takes place as the triceps muscle in the forelimb starts to contract?

Specialised cells, tissues and organs

A patient is suffering from a bacterial infection. A bacterial sample is collected to determine which antibiotic should be used for this patient. The diagram displays the test results. The shaded region indicates the area in which bacteria have grown. Which antibiotic is most effective against these bacteria?

Antibiotics

Which rows show some of the structures present in bacteria, fungi and viruses?

Features of organisms

The graph shows the mass of *Penicillium* grown in a fermenter alongside the mass of antibiotic produced. At what point is the *Penicillium* producing antibiotic at the fastest rate?

Antibiotics

The diagrams illustrate four different plant cells. Each one is performing aerobic respiration. Which diagram shows the movement of carbon dioxide molecules?

Diffusion and osmosis

The diagram illustrates the nitrogen cycle. During which stages of the nitrogen cycle are nitrogen-fixing bacteria important?

Nutrient cycles

Malaria is transmitted by the ……1……, which functions as a ……2…… for the disease. Which terms correctly fill in the sentence?

Disease

What rises over the long term because of tropical deforestation?

Effects of humans on ecosystems

The diagram shows a cross-section of a bean seed. Identify the labelled part that is the testa.

Sexual reproduction in plants

Which row identifies the two hormones needed for ovulation to happen?

Sexual reproduction in humans

The diagram illustrates the female reproductive system. In which part does fertilisation occur?

Sexual reproduction in humans

The illustration depicts a developing fetus inside the uterus. What is the name of the liquid at X?

Sexual reproduction in humans

Which human characteristic shows discontinuous variation?

Variation

Albinism is an inherited condition caused by a recessive allele. The diagram presents a family tree for a family affected by this condition. Individuals 9 and 11 have albinism. What is the probability that individual 10 is heterozygous?

Inheritance

The number of weed plants in a grass field was counted every month. The results are shown in the table. From August 2020 onwards, the field was mown on a regular basis and used as a football pitch. Using this information, which two weeds are most suited to surviving in mown grass?

Selection

The rate at which a root hair cell absorbed nitrate ions was measured at a range of soil nitrate concentrations. At $X$, the nitrate concentration in the soil is equal to that inside the cell. Which graph shows how the rate of absorption changes as the nitrate concentration in the soil changes?

Uptake and transport of water and ions

Human insulin genes may be introduced into bacteria. The bacteria can then be grown in culture and will make human insulin as a by-product. What advantage does a patient gain from using this source of insulin instead of insulin from animals?

Genetic modification

The graph illustrates how the reaction rate of a protease from the stomach changes with pH. What best describes the pH at point X?

Effects of temperature and pH

A dilute starch solution becomes blue after a very dilute iodine solution is introduced. As amylase breaks down the starch, this colour fades away. The graph shows how the blue colour disappears at different temperatures. Which statement explains the pattern of the curve?

Effects of temperature and pH

A plant has leaves with both green and white regions. One leaf is partly covered by aluminium foil, so that light cannot reach that part. The plant is then kept under a lamp for 24 hours. After this period, discs are removed from the labelled parts of the leaf shown and tested using iodine solution. Which leaf discs will turn blue-black when iodine solution is added?

Photosynthesis

A gardener is growing tomato plants in pots. At the start, the plants have green leaves and are growing rapidly. After a few weeks, the leaves become yellow. Which kind of water could the gardener give the plants to make the leaves green again?

Mineral nutrition

Which row identifies the diseases caused by a deficiency of different nutrients in the diet?

Diet

The diagram represents a plant cell. The cell has been stained using iodine solution. Once stained with iodine solution, what colours are shown by the cell wall and the starch grain?

Cell structure and function

Sometimes gall bladders become infected and must be removed by surgery. How would this affect the functioning of the body?

Human digestive system

What is one example of assimilation?

Absorption and assimilation

A student carried out an experiment to examine the rate of transpiration in a plant. The student prepared two identical apparatus setups. One was put in a room at $20^{\circ}\text{C}$ with bright light, and the other was put in a room at $20^{\circ}\text{C}$ in the dark. Which graph shows the student’s results?

Transpiration and translocation

What is the principal cause of water moving up to the leaves in xylem vessels?

Transpiration and translocation

Which blood vessels, connected directly to the heart, carry deoxygenated blood?

Blood vessels

The diagram illustrates the right side of the human heart while the ventricle is relaxed. Which row states the positions of valve X and valve Y as the ventricle contracts?

Heart

Which blood component triggers fibre formation to help seal a wound?

Blood

The diagram is of a cell. Which cell process is illustrated by the movement of substances shown in the diagram?

Diffusion and osmosis

Four flasks are sterilised and arranged as shown. Which flask will show evidence of fermentation (anaerobic respiration) after one hour?

Anaerobic respiration

The graphs display the depth and rate of breathing for one person carrying out four different activity levels. Each graph uses the same volume scale. Which graph indicates that the person is the most active?

Human gas exchange

Xylem vessels are cells adapted for conduction and support. Which two adaptations enable them to carry out these functions?

Uptake and transport of water and ions

Which graph illustrates how the concentrations of urea and glucose in the blood change during kidney dialysis?

Urinary system

The diagram presents a cross-section of human skin. Which structures take part in keeping body temperature constant?

Temperature control

The graph illustrates how a person’s body temperature varies with time. What could explain the changes in body temperature during periods 1 and 2?

Temperature control

The diagram shows a cross-section of the human brain. Which part of the brain controls the rate of breathing?

Mammalian nervous system

Which diagram illustrates the way light from a distant object is brought to a focus on the retina so that a clear image is formed?

Mammalian sense organs

Which condition leads to a higher blood glucose concentration?

Blood glucose control

The diagram displays the bones in the human forelimb. Which row correctly identifies the three bones?

Specialised cells, tissues and organs

Which short-term effect is brought about by excessive consumption of alcohol?

Mammalian nervous system

Which row presents the features of viruses?

Features of organisms

The graph illustrates the mass of $\textit{Penicillium}$ grown in a fermenter together with the mass of antibiotic produced. At what point is the $\textit{Penicillium}$ producing antibiotic at the fastest rate?

Biotechnology

What does diffusion mean?

Diffusion and osmosis

The diagram illustrates a section of the carbon cycle. Which row correctly identifies processes W, X, Y and Z?

Nutrient cycles

An organism, for example a mosquito, can transfer a disease-causing organism from one host to another. What term is used for the mosquito?

Disease

What rises over the long term because of tropical deforestation?

Effects of humans on ecosystems

Which graph shows the way the amount of DNA in a cell changes as the cell undergoes mitosis?

Nuclear division

The diagram illustrates the human male reproductive system. Which structure can hold sperm?

Sexual reproduction in humans

A number of statements about the human immunodeficiency virus (HIV) are given. Which of these statements about HIV are incorrect?

Disease

The diagram depicts a developing fetus inside the uterus. What is the liquid at X known as?

Sexual reproduction in humans

Which row gives examples of continuous and discontinuous variation in humans?

Variation

The family tree diagram illustrates the inheritance of eye colour. The allele for brown eyes is dominant, while the allele for blue eyes is recessive. Which people must have one brown-eye allele and one blue-eye allele?

Inheritance

The number of weed plants in a grass field was recorded at monthly intervals. The table gives the results. From August 2020 onwards, the field was mown regularly and used as a football pitch. Using this information, which two weeds are most suited to surviving in mown grass?

Features of organisms

The rate at which a root hair cell absorbs nitrate ions was determined at a range of nitrate concentrations in the soil. At $X$, the nitrate concentration in the soil matches the concentration inside the cell. Which graph illustrates how the absorption rate changes with the nitrate concentration in the soil?

Uptake and transport of water and ions

The stages involved in producing insulin on a commercial scale are given. Which order of events is correct?

Genetic modification

Amylase is an enzyme which converts starch into maltose. The students arranged an experiment to examine how different temperatures affect the action of amylase on starch solution. They recorded how much starch was still present after $30$ minutes at a range of temperatures. Which graph would you expect the students to draw from their results?

Effects of temperature and pH

Which statement shows the optimum (best) temperature for enzyme activity?

Effects of temperature and pH

A plant has leaves that contain both green and white regions. Part of one leaf is covered with aluminium foil so that light cannot reach it. The plant is then kept under a lamp for 24 hours. After this period, discs are taken from the parts of the leaf indicated and then tested using iodine solution. Which leaf discs will turn blue-black when iodine solution is added?

Photosynthesis

Which row indicates how nitrate ions affect plant growth and explains why this happens?

Mineral nutrition

The experiment illustrated was assembled and then left for 30 minutes. The membrane allows sugar and water through but does not allow starch or protein through. After 30 minutes, samples of the water in the beaker were tested using Benedict’s reagent, biuret reagent and iodine solution. What colours would be produced in these tests?

Diffusion and osmosis

The diagram depicts human skin.

Temperature control

A man chooses to start fitness training so that he can improve how well oxygen is supplied to his muscles.

Human gas exchange

A gardener cultivates a species of dahlia, which is a flowering plant. Each year, he picks his strongest plants and takes cuttings from them to produce new plants.

Asexual and sexual reproduction

The human liver has a large amount of enzymes known as transaminases. These enzymes play a key role in amino acid metabolism. Amino acids are taken up from the alimentary canal and transported to the liver in a blood vessel.

Enzyme action

A species of plant is found in ponds. The diagrams present the complete plant and a transverse section through one of its leaves.

Leaf structure

There are many kinds of virus that are able to infect animal cells.

Cell structure and function

The diagram presents a cross-section through a human molar tooth.

Diffusion and osmosis

Nerve impulses and hormones coordinate body functions.

Mammalian nervous system

Worldwide, more than 100 million tonnes of nitrogen-containing fertiliser are made each year. Farmers then scatter this artificial fertiliser onto their soil.

Mineral nutrition

The diagram displays the human brain, and the table gives the functions of some of its parts.

Temperature control

The diagram displays apparatus for investigating breathing.

Human gas exchange

A student conducted two investigations on the action of yeast.

Enzyme action

Phenylalanine is one of many different amino acids. The diagram presents the structure of a phenylalanine molecule.

Inheritance

Environmental conditions affect biological processes in plants.

Transpiration and translocation

The diagram shows food in a section of the small intestine.

Human digestive system

The diagram presents a cross-section of a seed before germination and shows the same seed again after it has developed into a seedling.

Nuclear division

Compare the pulmonary artery and the vena cava in relation to their structure and function.

Blood vessels

Compare the ureter and the urethra in relation to their functions in adult humans.

Urinary system