May/June 2017

The diagram illustrates cells taken from a plant leaf. Which structure is rich in magnesium?

Photosynthesis

A person has an obstruction in their bile duct. What would be the consequence of this?

Human digestive system

Water and ions can move to the xylem of a plant root along the cell walls, without crossing a cell membrane. By what process do these substances pass through the cell walls?

Uptake and transport of water and ions

An area of grassland is covered by sea-water. Sea-water has a very high salt concentration. What effect does the sea-water have on the functions of the root hairs?

Diffusion and osmosis

Which heart chamber has the thickest walls?

Heart

Which row gives the blood pressures for an artery, a capillary and a vein?

Blood vessels

State one difference between plasma and tissue fluid.

Blood

What changes take place in the diaphragm and intercostal muscles as a person breathes in?

Human gas exchange

What is produced during anaerobic respiration in muscles?

Anaerobic respiration

The graph illustrates how the volume of air in a person’s lungs changes during a 30-second interval. During which time interval is the breathing rate highest?

Human gas exchange

A breakdown of the composition of expired air is displayed. Using only the information in the table, what percentage of the expired air is excreted material?

Human gas exchange

Which of the following processes will always take place down a concentration gradient?

Diffusion and osmosis

Which sections of the skin take part in controlling body temperature?

Temperature control

A person is viewing some distant hills. Which row shows the condition of the lenses, ciliary muscles and suspensory ligaments in her eyes?

Mammalian sense organs

What are the features of hormones?

Mammalian hormones

The diagram illustrates some of the nerve pathways involved in a reflex action. If the pathway at X is damaged, what effect does this have on the reflex?

Mammalian nervous system

The diagram illustrates several of the bones and muscles in a human arm. Which option correctly describes the changes that make the forearm rise?

Specialised cells, tissues and organs

Which one of these diseases can antibiotics treat effectively?

Antibiotics

The diagram illustrates several features of different organisms. What do areas X and Y stand for?

Concept and use of a classification system

The diagram shows a simple apparatus that could be used to make alcohol. What function does the U-shaped tube filled with water serve?

Anaerobic respiration

Why must an ecosystem receive regular exposure to sunlight?

Energy flow

The diagram represents a food chain. tree  mice  cats  fleas What form would the pyramid of numbers take for this food chain?

Energy flow

A student prepares four potato cylinders. Each cylinder is $30\,\text{mm}$ in length. The cylinders all have the same diameter. The potato cylinders are then put into sugar solutions with different concentrations. After one hour, the lengths of the cylinders are measured again. The results are shown in the table. Which sugar solution has a water potential nearest to that of the potato cells?

Diffusion and osmosis

The diagram illustrates part of the nitrogen cycle. Which process takes place at X?

Nutrient cycles

Which row identifies the malarial parasite and the vector responsible for transmitting it?

Disease

Which plants are most likely to adapt successfully when the climate in their environment changes?

Selection

The diagram shows a flower sectioned into two halves. Which two parts of the flower produce haploid gametes?

Sexual reproduction in plants

The diagram illustrates several stages of cell division in a fruit fly. Cell X has 8 chromosomes. How many chromosomes are present in cell Y and in cell Z?

Nuclear division

What route do sperm cells follow during ejaculation from the male reproductive system?

Sexual reproduction in humans

Which row gives a sign, a symptom and a treatment for syphilis in males?

Disease

Which of the following statements concerning genes and chromosomes is correct?

DNA

Which characteristic of bacteria displays discontinuous variation?

Variation

Across many hundreds of years, the milk production of a specific kind of farm animal has risen steadily. How has this been achieved?

Selection

What are the properties of enzymes?

Enzyme action

In fruit flies, the allele for an ebony-coloured body is recessive to the allele for a grey-coloured body. In an investigation, a fly with an ebony body is crossed with a fly with a grey body. What will be the body colour of the offspring if the grey-bodied fly is heterozygous?

Inheritance

The diagram shows several substances present in plant cells. Which part of the diagram shows the end products of photosynthesis?

Photosynthesis

Test-tubes P and Q were each filled with a solution of red hydrogencarbonate indicator. Hydrogencarbonate indicator turns yellow when the carbon dioxide concentration increases and turns purple when the carbon dioxide concentration decreases. Equal pieces of the same aquatic plant were placed in tubes P and Q. Tube P was left uncovered, while tube Q was covered with a black light-proof cover. The tubes were kept for four hours in a warm room in sunlight. What would be the colour of the hydrogencarbonate indicator in the two tubes after four hours?

Photosynthesis

Which graph illustrates the effect of temperature on the rate of photosynthesis?

Photosynthesis

Certain people wear clothes that leave only a small part of their skin exposed. This puts them at risk of a deficiency disease when sunlight is limited. Which nutrient is missing from their diet?

Diet

Which is not one of the liver's functions?

Human digestive system

The diagram illustrates cells taken from a plant leaf. Which structure has a high concentration of magnesium?

Leaf structure

In which blood vessel does the glucose concentration change the most?

Blood vessels

Which characteristic of root hairs indicates that ions are absorbed from the soil by active transport?

Active transport

A cut shoot from a plant is put into a beaker of blue dye solution for one hour, as illustrated. The stem of the shoot is then sliced at X and viewed with a microscope. In which part of the stem is the blue dye concentrated most strongly?

Uptake and transport of water and ions

Why does an increase in pulse rate matter to an athlete during a $200\,\text{m}$ race?

Heart

Which row identifies a factor that may lead to coronary heart disease?

Disease

State one way in which plasma and tissue fluid are different.

Blood

What forms the lining of the alveolar walls?

Human gas exchange

Which substances are formed during aerobic respiration?

Aerobic respiration

The graph illustrates how the volume of air in a person’s lungs varies during a $30\,\text{s}$ interval. During which time interval is the breathing rate highest?

Human gas exchange

The diagram shows dialysis in a kidney machine. Every shape stands for a molecule present in blood or in dialysis fluid. Which shape stands for protein?

Urinary system

Which of these statements about diffusion are correct?

Diffusion and osmosis

Which sections of the skin take part in regulating body temperature?

Temperature control

Through which structures does light travel when it is brought to a focus on the retina?

Mammalian sense organs

Which row indicates what triggers the release of adrenaline or insulin, and the effect of that hormone on blood glucose concentration?

Blood glucose control

A man sustains an injury to his head, and his cerebellum is damaged. What is the outcome of this?

Mammalian nervous system

The diagram shows four bones linked to the forelimb. Which bones make up a hinge joint?

Specialised cells, tissues and organs

The diagram shows an experiment arranged to compare the effectiveness of different antibiotics against a species of bacterium. In this experiment, which conditions need to be kept constant?

Antibiotics

The diagram illustrates stages involved in cheese production. During which stage does pH fall significantly?

Anaerobic respiration

The diagram illustrates a cell and some of its features. From which part has this cell been obtained?

Specialised cells, tissues and organs

Why is it necessary for an ecosystem to receive sunlight at regular intervals?

Energy flow

The diagram illustrates part of the nitrogen cycle. Which process takes place at X?

Nutrient cycles

Which row gives the definition of active transport?

Active transport

The leaves of a tree are eaten by insects. Those insects are then eaten by small birds, which are themselves preyed on by larger birds. Which pyramid of numbers shows this food chain?

Energy flow

Which row shows the correct pairing of a method used to control malaria with an explanation of how it works?

Disease

Which plants are most likely to adapt successfully when the climate changes in their environment?

Selection

The diagram depicts a cross-section of a plum fruit. Which structure has a genotype that differs from the other three?

Sexual reproduction in plants

The diagram illustrates several stages of cell division in a fruit fly. Cell X contains 8 chromosomes. How many chromosomes are present in cell Y and in cell Z?

Nuclear division

What route do sperm cells follow from the male reproductive system during ejaculation?

Sexual reproduction in humans

Which birth-control method offers some protection against syphilis and HIV?

Sexual reproduction in humans

What is required for natural selection to take place?

Selection

Insulin is produced on a commercial scale by means of genetic engineering. Which kind of organism is employed to make large amounts of insulin in this manner?

Genetic modification

Which statement concerning chromosomes is correct?

DNA

Which property of enzymes is accounted for by the lock and key hypothesis?

Enzyme action

In fruit flies, the allele for an ebony coloured body is recessive compared with the allele for a grey coloured body. During an investigation, a fly with an ebony body is crossed with a fly with a grey body. If the grey-bodied fly is heterozygous, what body colour will the offspring have?

Inheritance

The diagram shows several substances present in plant cells. Which part of the diagram indicates the final products of photosynthesis?

Photosynthesis

Two test-tubes, P and Q, were prepared, and each one contained a solution of red hydrogencarbonate indicator. Hydrogencarbonate indicator becomes yellow when the carbon dioxide concentration rises and turns purple when the carbon dioxide concentration falls. Matching pieces of the same aquatic plant were put into tubes P and Q. Tube P was left uncovered, whereas tube Q was covered with a black light-proof cover. The tubes were then kept in a warm room in sunlight for four hours. What colour would the hydrogencarbonate indicator be in the two tubes after four hours?

Photosynthesis

Which graph illustrates how temperature affects the rate of photosynthesis?

Photosynthesis

Which symptom of malnutrition can be relieved by increasing the amount of protein in the diet?

Diet

The diagram illustrates the human alimentary canal. In which part does protein digestion start?

Human digestive system

Spirulina is placed in the bacteria group. It is green in colour and can synthesise its own food.

Features of organisms

A potometer is an instrument for measuring the uptake of water by a plant. Fig. 2.1 shows a plant stem and flower placed in a potometer. When water is taken in, the bubble travels in the direction shown.

Transpiration and translocation

Fig. 3.1 shows organ X together with the blood vessels P, Q and R linked to it. Organ X is involved in amino acid metabolism and in the breakdown of chemical substances, including alcohol.

Mammalian hormones

Fig. 4.1 presents a Bengal tiger. The fur colour of the Bengal tiger is determined by one gene. The gene’s dominant allele gives orange fur. A single alteration in this gene creates a recessive allele, which gives white fur in tigers with the homozygous recessive genotype.

Inheritance

The statements E to K concern the process of reproduction. Table 5.1 compares sexual reproduction with asexual reproduction.

Asexual and sexual reproduction

Describe what the cilia in the trachea do.

Specialised cells, tissues and organs

Fig. 7.1 shows bacteria growing on the surface of a dish of nutrient jelly. Paper discs, for example M and N, were first soaked in different antibiotic solutions and then placed on the bacterial growth. A transparent region in the jelly shows that the bacteria there have been killed.

Selection

Using named components, describe how one animal cell (such as a fresh liver cell) would differ in structure from a plant cell (such as an onion epidermal cell).

Cell structure and function

Compare aerobic respiration with anaerobic respiration.

Respiration

Fig. 1.1 presents the front view of a person’s chest and abdomen.

Human gas exchange

The stages of human nutrition listed here are: ingestion, digestion, absorption, egestion. Fig. 2.1 displays the human alimentary canal.

Human digestive system

Fig. 3.1 shows flowers of the same plant species at two different developmental stages, D and E.

Sexual reproduction in plants

Table 4.1 compares the loss of water vapour from two similarly sized potted plants, F and G, which were grown in the same environment over 14 hours.

Transpiration and translocation

Fig. 5.1 displays cells from which some structures have been omitted.

Cell structure and function

Describe the route taken by a carbon dioxide molecule after it is formed by respiration in a body cell, up to the point where it enters the air inside the lungs.

Blood vessels

Fig. 7.1 shows a cross-section through a fruit.

Sexual reproduction in plants

A simple food chain is shown here: tree → insect → bird → fox

Energy flow

Explain the measures used, apart from drugs, to cut the spread of malaria.

Disease