Oct/Nov 2022

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

Photosynthesis

The diagram illustrates an experiment. After $30$ minutes, tests were done on the contents of the membrane bag and on the water in the beaker. Which row gives the test results?

Diffusion and osmosis

Which function is not one of the jobs carried out by the liver?

Human digestive system

Which of the following statements about root hairs are correct?

Specialised cells, tissues and organs

The graph presents the transpiration rates of two plants over the course of a single day. The two plants were grown in identical conditions. Which statement accounts for what the graph shows?

Transpiration and translocation

Certain people are born with a rare heart disorder in which the lower left chamber of the heart has not developed normally and is much smaller than usual. As a direct effect of this disorder, blood flow to which blood vessel is reduced below the normal level?

Heart

The body usually rejects tissue transplants unless the donated tissue and the patient are matched very closely. Which blood component is responsible for causing rejection of transplanted tissue?

Immunity

The diagram illustrates the transfer of substances between blood in a capillary and tissue fluid. Through which process does water move from tissue fluid into the capillary?

Diffusion and osmosis

The apparatus is arranged as shown. Test-tubes $1$ and $2$ each contain limewater. Limewater is a clear solution that becomes cloudy when carbon dioxide is present. Air is pumped through the apparatus. What will the limewater look like in test-tubes $1$ and $2$ after $10$ minutes?

Photosynthesis

Which equation shows anaerobic respiration in yeast?

Anaerobic respiration

The graph illustrates the rate and depth of breathing when the body is at rest. Which graph represents the rate and depth of breathing during exercise?

Human gas exchange

What roles are carried out by xylem vessels?

Uptake and transport of water and ions

In what way do the concentrations of oxygen and urea in the renal artery differ from their concentrations in the renal vein?

Urinary system

What changes take place when a person moves from a very cold room into a hot room?

Temperature control

The diagram shows a cross-section of part of the skin. Which structure is the most effective insulator?

Specialised cells, tissues and organs

The graph illustrates how the shape of the lenses in a person's eyes changes while they are watching a bird in flight. At which point is the bird moving towards the person at the greatest speed?

Mammalian sense organs

The diagram illustrates the nerve pathway involved in a reflex action when a person accidentally touches something hot. Which row correctly names a sensory neurone, a relay neurone and a motor neurone?

Mammalian nervous system

A patient presents with symptoms of unexplained weight loss, intense thirst and a frequent urge to urinate. A test reveals a high concentration of glucose in the urine. Which condition is diagnosed?

Blood glucose control

The diagram illustrates the forelimb of a rabbit. Which labelled bone is the ulna?

Specialised cells, tissues and organs

Which activity is most likely to lead to lung disease?

Disease

The table presents some characteristics of three kinds of microorganism. Which row correctly matches each type of microorganism?

Concept and use of a classification system

Two containers, X and Y, were each given the same amount of dough mixture for bread-making. Yeast was added to the mixture in Y. Both containers were then kept in a warm place for two hours. The diagram shows how they looked after this time. Which substance made by the yeast causes the difference between the dough in X and Y?

Anaerobic respiration

A diagram of a typical plant cell is shown after it has remained in a concentrated salt solution for 10 minutes. Which numbered structures are partially permeable?

Diffusion and osmosis

Which kinds of microorganism perform decomposition in the nitrogen cycle?

Nutrient cycles

Which measures may be used to control the malarial pathogen?

Disease

The graph illustrates the dissolved oxygen concentration at various locations along a river. At which point is sewage discharged into the river?

Effects of humans on ecosystems

The diagram illustrates bees visiting a flowering plant species with tall spikes of flowers. In the flowers at the base of the spike, the carpels are mature whereas the anthers are still immature. In the flowers at the top of the spike, the anthers are mature whereas the carpels are still immature. Which statements are correct?

Sexual reproduction in plants

The diagram illustrates a cross-section of a dicotyledonous seed. Which structure supplies most of the nutrients required for the seed’s growth after germination?

Sexual reproduction in plants

Human gametes are not all the same. Which statement about male gametes is correct?

Sexual reproduction in humans

The diagram represents the menstrual cycle. The numbers indicate how many days have passed since menstruation began. Which label marks the point in the cycle at which implantation is most likely to happen?

Sexual reproduction in humans

One snail variety has an inherited condition that changes the shell thickness. $S^t S^t$ have thick shells. $S^t S^n$ have thin shells. $S^n S^n$ do not survive. Two heterozygous snails are crossed. What is the probability that a surviving snail in the next generation is a heterozygote?

Inheritance

A man with blood group A and his wife, who has blood group O, had two children; both children were blood group A. He decided that he must be homozygous for the allele $I^A$, because he believed that, if he were heterozygous, half of his children would have group O. Why is his conclusion invalid?

Inheritance

In a garden, there is an insect species that may be red or green in colour. The green insects are very well camouflaged. Birds that feed on insects begin to live in the garden. The graph shows how the numbers of red and green insects then change. What is this an example of?

Selection

Which row is correct for active transport?

Active transport

What benefits can genetic engineering of crops bring?

Genetic modification

Which of the following statements are correct?

Cell structure and function

The diagram illustrates the effect of temperature on the rate of an enzyme-controlled reaction. What explains the part of the graph labelled X?

Effects of temperature and pH

A small mountain lake contains aquatic plants growing beneath the water on the lake bed. Soon after heavy rainfall, the mud on the lake bed is disturbed and the water level increases. Why does this lead to a decrease in the rate of photosynthesis in these plants?

Photosynthesis

Some plants are growing well and have large leaves, but the leaves are becoming yellow. Which factor is most likely to be causing this problem?

Mineral nutrition

Which row gives the average daily energy requirement for the people listed in the table?

Diet

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

Leaf structure

The diagram illustrates the processing of food in the human alimentary canal. Which row correctly names the stages?

Human digestive system

Which function is not performed by the liver?

Excretion

Which of the following statements about root hairs are correct?

Specialised cells, tissues and organs

The table presents weather conditions in a field. Which row indicates the conditions that would make a plant wilt most quickly?

Transpiration and translocation

In some people, a rare heart condition means that the heart’s lower left chamber has failed to develop correctly and is far smaller than usual. As a direct consequence of this condition, blood flow into which blood vessel is reduced below the normal level?

Heart

Through what route does blood travel around the body?

Circulatory system

The diagram illustrates the movement of materials between blood in a capillary and tissue fluid. Which row gives the correct labels for the arrows in the diagram?

Blood vessels

The apparatus is arranged as illustrated. Test-tubes 1 and 2 each contain limewater. Limewater is a colourless solution that becomes cloudy when carbon dioxide is present. Air is pumped through the apparatus. What will the limewater in test-tubes 1 and 2 look like after 10 minutes?

Respiration

Fitness training for athletes lowers the need for anaerobic respiration. It also increases the speed at which lactic acid is removed after exercise. The table gives the concentration of lactic acid in the blood of four different athletes. They exercise for 20 minutes and then rest for the following 70 minutes. The lactic acid concentration is measured in $\text{mg per }100\,\text{cm}^3$ of blood. Starting with the fittest athlete and ending with the least fit, which sequence is correct?

Anaerobic respiration

The diagram illustrates the human gas exchange system. Which row gives the correct labelling?

Human gas exchange

The diagram shows the cell structures of a bacterial cell, a liver cell, an onion epidermal cell and a red blood cell. Which structure is shown by X?

Cell structure and function

Which two key functions do the kidneys perform?

Urinary system

What changes take place when a person moves from a very cold room into a hot room?

Temperature control

The graph illustrates measurements of one feature of the human body’s internal environment recorded over time. What regulates the internal environment of the human body so that each feature stays within tight limits?

Homeostasis

If a bright light is directed into the eye, the pupil contracts. Which statement explains this reaction?

Mammalian sense organs

The flow chart shows a reflex action. a painful stimulus is detected by a ...E... → the impulse is carried by a ...F... neurone → the impulse is transferred to the ...G... neurone through the ...H... neurone → finally the impulse is carried to the ...I... to produce a response. Which row correctly completes the flow chart?

Mammalian nervous system

A patient has symptoms of unexplained weight loss, extreme thirst and a frequent need to urinate. A test reveals a high level of glucose in the urine. Which condition is diagnosed?

Blood glucose control

Which graph illustrates the lengths of the biceps and triceps muscles in the upper arm when the elbow joint is fully extended and the arm is straight?

Mammalian nervous system

Four discs, A, B, C and D, each of which contained a different antibiotic, were put onto agar gel in a Petri dish. The agar gel contained $E.\ coli$ bacteria. The Petri dish was then sealed and left to incubate for 24 hours at $35\,^\circ\text{C}$. The results are shown. Which antibiotic is the most effective?

Antibiotics

Bacteria, fungi and viruses are frequently classified together as microorganisms. Which statement about microorganisms is correct?

Concept and use of a classification system

Two containers, X and Y, were each filled with the same quantity of dough mixture for bread-making. Yeast was added to the mixture in Y. Both containers were then kept in a warm place for two hours. The diagram shows how they looked after this period. Which substance made by the yeast is responsible for the difference between the dough in X and Y?

Anaerobic respiration

The diagram represents a typical plant cell that has been placed in a concentrated salt solution for $10$ minutes. Which numbered structures are partially permeable?

Diffusion and osmosis

What is the main source of energy entering biological systems?

Energy flow

In the carbon cycle, through which process can carbon enter the atmosphere?

Nutrient cycles

The graph illustrates the concentration of dissolved oxygen at various positions along a river. At which point is sewage discharged into the river?

Effects of humans on ecosystems

A gardener has two sets of strawberry plants, named X and Y. They are cultivated to maturity in identical conditions. He records several observations and decides that the plants in group X were formed asexually and those in group Y were raised from seeds. Which observations provide the strongest support for his conclusions?

Asexual and sexual reproduction

The diagram shows a cross-section of a flower. In which part does fertilisation happen?

Sexual reproduction in plants

Human gametes are not all identical. Which statement about male gametes is correct?

Sexual reproduction in humans

In the menstrual cycle, hormone M is secreted in the body and triggers the formation of eggs. After that, hormone N is released and causes ovulation. What are the names of hormones M and N?

Sexual reproduction in humans

What is the right sequence for the sizes of the genetic material pieces listed in the table, from the smallest to the largest?

DNA

A man with blood group A and his wife with blood group O had two children, and both were blood group A. The man decided that he had to be homozygous for the allele $I^A$, because he believed that if he were heterozygous then half of his children would have been blood group O. Why was this conclusion unsound?

Inheritance

As carbon dioxide concentrations in the atmosphere rise, the Earth’s climate is warming. How could this climatic change influence natural selection?

Selection

Which process is responsible for transporting nitrate ions into the cell shown?

Active transport

A gene responsible for insulin production can be moved from human DNA into bacterial DNA. The bacteria are then grown to make human insulin. What advantage does this type of human insulin have for patients compared with insulin taken from other animals?

Genetic modification

Fats are split by the enzyme lipase to yield fatty acids and glycerol. In the ‘lock and key’ model of enzyme action, what represents the ‘lock’ and what represents the ‘key’ in this reaction?

Enzyme action

The graph shows how the activity of four enzymes, A, B, C and D, changes as $\text{pH}$ varies. Which enzyme functions in the stomach?

Effects of temperature and pH

A small mountain lake contains aquatic plants growing below the water on the lake bed. Soon after heavy rainfall, the sediment on the lake bed is disturbed and the water level increases. Why does this make the photosynthesis rate of these plants decrease?

Photosynthesis

The graph illustrates how the yield of a wheat crop changes when different amounts of nitrate fertiliser are added. What conclusion can be drawn from the graph?

Mineral nutrition

A shortage of some minerals and vitamins can cause deficiency diseases. Which row identifies the correct symptoms of these diseases?

Diet

The diagram illustrates the sections of the human body that take part in excretion.

Urinary system

Grapes are fruits that develop on a plant known as a grape vine. A farmer cultivates a type of grape vine called the sultana. The grapes that are produced are sold either for eating fresh or for making dried fruit known as sultanas.

Photosynthesis

Guinea pigs are small mammals. In some countries they are kept as a food source, while in others they are bred and sold as pets.

Inheritance

Amylases are enzymes produced by specific cells in animals and plants, and bacteria also make them. In humans, amylase is released into the alimentary canal in saliva and in pancreatic juice.

Enzyme action

Lions are carnivorous mammals that prey on other animals. A lion’s forelimb is built on the same basic plan as a human arm.

Anaerobic respiration

The diagram illustrates several cells from the lower region of a leaf that is transpiring.

Transpiration and translocation

Humans possess receptors that sense stimuli in their surroundings, together with a nervous system that coordinates the responses to those stimuli.

Mammalian nervous system

Malnutrition is a worldwide issue. In early 2020, the global population was about 7.8 billion people. From this total, it is estimated that 1.9 billion adults were overweight and 462 million were underweight.

Diet

Describe the make-up of human blood.

Blood

The organs in the human body make substances that each have a particular function.

Mammalian hormones

A light microscope view shows a leaf in cross-section.

Leaf structure

The graph illustrates how lactose concentration changes over 48 hours as milk is converted into yoghurt.

Biotechnology

The diagram illustrates the heart’s internal arrangement and the blood vessels connected to it.

Heart

A team of scientists studied the total mass of carbon dioxide released when animals and plants are reared on farms and then eaten by humans as food.

Effects of humans on ecosystems

The diagram presents a food web in a grassland habitat.

Energy flow

The picture shows a tomato plant fruit that has been sliced in two so the parts marked P and Q can be seen.

Sexual reproduction in plants

Describe and explain the gas exchange between a plant leaf and the surrounding atmosphere over a 24-hour cycle.

Transpiration and translocation

Explain the advantages and disadvantages of using insecticides in agriculture.

Disease