May/June 2024

The diagram displays some structures found in a plant cell. Which labelled parts indicate a sap vacuole, a nucleus and a chloroplast?

Cell structure and function

A student carried out an investigation into the rate of transpiration in a green plant. The plant was growing in soil inside a pot. After watering the plant, the student placed a plastic bag around the pot while keeping the leaves outside the bag. She recorded the mass of the plant and pot at the beginning, then repeated the measurement every two hours for six hours. The findings from the investigation are shown. What is the mean rate of transpiration during the six-hour period?

Transpiration and translocation

The diagram illustrates what happens to amino acids in one part of the human body. What describes processes P and Q?

Excretion

A dish contains agar jelly with starch. Four holes are made in the jelly, and each one is filled as shown in the diagram. After $30\,\text{minutes}$, which hole will be enclosed by the greatest starch-free area?

Enzyme action

A healthy person consumes a meal that includes carbohydrates. After two hours, which structure would hold a fluid with a higher glucose concentration?

Absorption and assimilation

Which cells in the gas exchange system are responsible for mucus production?

Human gas exchange

Which equation shows anaerobic respiration in humans?

Anaerobic respiration

The heart functions as a pump, forcing blood around the circulatory system. The arrows on the heart diagram show the direction of blood flow. At which point is the pressure of the blood greatest?

Heart

A person’s cuts and grazes fail to heal, and their blood does not clot readily. What might be causing these symptoms?

Blood

By what route is the malarial parasite passed to humans?

Disease

Some fatal diseases are linked to smoking tobacco. In 1990, the government of a country started a campaign to encourage people to give up smoking. The graph shows the numbers of people dying from smoking-related diseases in the years following 1990. If the number of people dying from smoking-related diseases kept falling at the same rate, in which year would there be no deaths caused by smoking?

Disease

A previously unknown organism is found. It has DNA within a cellular structure. Which group of organisms might it belong to, and which group might it not belong to?

Concept and use of a classification system

Which diseases are treated effectively using antibiotics?

Antibiotics

In 2022, a number of countries made it compulsory for travellers to be fully vaccinated against the COVID-19 virus. New Zealand’s rule said: ‘You need to have had the last vaccination at least 14 days before you arrive.’ Why did New Zealand insist on a 14-day gap after vaccination before entry was permitted?

Immunity

Which row shows the components found in urine in a healthy person?

Urinary system

Which statement explains the functions of the parts of the nervous system?

Mammalian nervous system

The diagram illustrates a cross-section of the eye. For the pupil reflex, which row correctly identifies where the receptors and effectors are located?

Mammalian sense organs

The graph illustrates how a person's body temperature changes during a 60-hour period. Which statement about the graph is correct?

Temperature control

Which process is activated by adrenaline in liver cells?

Blood glucose control

The diagrams illustrate experiments used to study how plant shoots respond to light. Which shoot will not grow towards the light?

Coordination and response in plants

The diagram illustrates the life cycle of one species of plant. In which stage does meiosis (reduction division) take place?

Sexual reproduction in plants

State one advantage of sexual reproduction in plants.

Sexual reproduction in plants

If animal cells and plant cells are put into distilled water, the animal cells burst whereas the plant cells do not. Which statement accounts for this difference?

Diffusion and osmosis

The table gives some characteristics of four flowers, A, B, C and D. Which flower is most likely to be pollinated by wind?

Sexual reproduction in plants

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

Sexual reproduction in humans

The diagram presents the female reproductive system. Which label points to the cervix?

Sexual reproduction in humans

The graph illustrates the percentage of the population that has the different ABO blood groups in one region. How does the graph indicate that variation in ABO blood groups is discontinuous?

Variation

For a gene with two alleles, $A$ and $a$, which diagram shows these alleles and the genotypes they can produce?

Inheritance

As time passes, a bird species acquires a beak that is more pointed. This pointed beak enables the birds to पकड़? no English. It helps them catch small insects that may be concealed in cracks in the rocks. What is one reason for the change in the shape of the birds’ beaks?

Selection

During the genetic modification process used to produce artificial insulin (a protein), what material is introduced into the host bacterium, and what consequences does this produce?

Genetic modification

The diagram presents a food web from an ecosystem. Which group of organisms in an ecosystem is missing from this food web?

Energy flow

The graph illustrates atmospheric carbon dioxide concentration in a country from 1968 to 2000. Carbon dioxide concentration changes from year to year. What is the best explanation for these variations?

Nutrient cycles

The diagrams illustrate how rain is affected when it falls on an area of forested land both before and after houses are constructed. Before houses are built, rainfall is $100\%$, with transpiration at $40\%$, surface runoff at $10\%$ and groundwater at $50\%$. After houses are built, rainfall is $100\%$, transpiration at $25\%$, groundwater at $32\%$ and surface runoff $?\%$. What is the difference in the percentage of surface runoff before and after the houses are built?

Effects of humans on ecosystems

The diagram shows the concentration of magnesium ions in a root hair cell of a healthy plant and in the soil water around the root hair cell. The plant is constantly using magnesium ions. To keep the plant healthy, in which direction will the magnesium ions move?

Uptake and transport of water and ions

The graph plots the oxygen concentration in a river at stations $1$ to $5$, with each station $100\,\text{m}$ apart. A sewage outflow is located just after station $1$. At which stations are the concentrations of organic matter the lowest?

Effects of humans on ecosystems

The key is made up of shapes that stand for small food molecules. Large food molecules are formed from smaller food molecules. Which diagram shows a section of a glycogen molecule?

Biological molecules

Enzymes are biological catalysts. Which sort of molecule is able to function as an enzyme?

Biological molecules

The graphs illustrate factors that affect the rate of photosynthesis. At which points on the graphs might light intensity be limiting the rate of photosynthesis?

Photosynthesis

The diagram illustrates a cross-section of a leaf. What are the functions of the parts labelled 1, 2, 3 and 4?

Leaf structure

Which route is followed by water and mineral ions through a plant?

Uptake and transport of water and ions

Which kind of cell contains a cellulose cell wall?

Cell structure and function

The graph illustrates the amount of water vapour lost by two different plants that are growing under identical conditions. What could explain the difference in the volume of water vapour lost from the two plants?

Transpiration and translocation

The diagram illustrates some parts of the human digestive system. Which row states the main function of each labelled part?

Human digestive system

A dish is filled with agar jelly that contains protein. Four holes are made in the jelly, and each hole is filled as shown in the diagram. After 30 minutes, which hole will have the greatest area around it with no protein?

Enzyme action

Scientists estimated the surface areas of the internal walls of several parts of a healthy human digestive system. Which region is the small intestine?

Human digestive system

The diagram illustrates an alveolus and a blood capillary. Which row names the letters P, Q and R?

Human gas exchange

What substance is made during anaerobic respiration in muscles?

Anaerobic respiration

A student recorded their pulse rate in beats per minute (bpm) three times while resting and three times after running. The table lists the results. What was the mean heart rate after running, rounded to the nearest bpm?

Heart

During heart surgery, a heart and lung bypass machine is used so that the heart can be stopped while the procedure is carried out. Blood is taken from the blood vessel that carries it into the heart from the body and diverted through the bypass machine. The machine adds oxygen to the blood and then pumps it back into the blood vessel that carries it away from the heart so it can return to the body. In which blood vessels are the tubes inserted to take blood from the body to the bypass machine and to send the blood back to the body?

Blood vessels

Records of the yearly number of people who suffer from malaria in countries across the world have been gathered for many years. Some of these data are shown in the table. Which country had a number of people suffering from malaria in 2019 $50\%$ lower than in 1990?

Disease

Which disease has a strong link with cigarette smoking?

Disease

A number of young plants were planted in the soil and developed normally for several weeks. After that, they started to show symptoms of disease. A microscope was used to look at samples taken from the diseased leaves. Which features seen in the organism responsible for the disease indicate that it may be a fungus?

Features of organisms

Four sets of people (A, B, C and D) were exposed to a pathogenic virus infection. Scientists recorded the amount of antibodies in their blood both before and after infection. The findings are shown in the graphs. PAL is the Protective Antibody Level - the amount needed to provide protection against the virus. Which group of people would have experienced the effects of the viral infection?

Immunity

Give one example of excretion.

Excretion

The diagram illustrates an amino acid molecule. Which section of the amino acid molecule is removed and then used to produce urea?

Excretion

What role do sensory neurones perform?

Mammalian nervous system

A list of the alterations that happen in the eye is shown below. 1 Ciliary muscles contract. 2 Ciliary muscles relax. 3 Suspensory ligaments become slack. 4 Suspensory ligaments tighten. 5 The lens becomes more spherical. 6 The lens becomes thinner. 7 Light rays are refracted less. 8 Light rays are refracted more. Which row shows the changes that happen when focusing on distant and near objects?

Mammalian sense organs

A student is going along a road when a friend, who is concealed, suddenly leaps out and startles her. Which graph shows how adrenaline affects the student’s heart rate following the shock? (X on the graph marks the point at which the student’s friend suddenly leaps out.)

Mammalian hormones

What is one symptom of Type 1 diabetes?

Blood glucose control

Five experiments were used to study the phototropic response of shoots. The diagrams illustrate how the plants' growing shoots were treated. Which shoot tips displayed a positive phototropic response when light was directed at them from one side?

Coordination and response in plants

A student made some mistakes in statements about chromosomes. 1 A human body cell has $46$ pairs of chromosomes. 2 Chromosomes are found in pairs in gametes. 3 Each body cell in a male has one $X$ chromosome and one $Y$ chromosome. 4 A chromosome contains one long DNA molecule that is divided into sections called genes. 5 Genes are split into sections called DNA molecules, which are included in chromosomes. Which two statements are correct?

DNA

This seaweed inhabits shallow waters near the coast. The stages of its life cycle are illustrated. At which points in its life cycle are its cells diploid?

Sexual reproduction in plants

An enzyme is used to remove the cell wall from a plant cell. What would occur if this cell were then put into distilled water?

Diffusion and osmosis

The diagram illustrates a carpel following pollination. Pollen grains from two different species of flower have landed on the stigma. What accounts for the different germination of the two kinds of pollen grains shown?

Sexual reproduction in plants

In human reproduction, which order of events is correct?

Sexual reproduction in humans

The diagram illustrates the female reproductive system during pregnancy. Which labelled structure eliminates the excretory products of the fetus?

Sexual reproduction in humans

Three of the four graphs displayed were drawn from data gathered on how specific characteristics vary within a population. Which graph was not drawn from this type of data?

Variation

The diagram illustrates three generations of a family tree in which an inherited disorder affecting the nervous system appears. This disorder is caused by a dominant allele that usually produces its effect in adulthood. The woman, 4, is showing symptoms of this disorder while she is pregnant. What is the probability that the new baby, 7, will be a girl who will also develop the disorder later in life?

Inheritance

Which process is reproduction carried out by the members of a species that are most suited to their environment?

Selection

During an industrial process, milk is allowed to flow over jelly beads that contain the enzyme lactase. As the milk moves across the beads, it will make contact with lactase. By point X, all digestion of the milk has been completed. What is collected at X?

Enzyme action

Within Africa’s grasslands, large herbivores, for example elephants, carry many parasites, including ticks. These ticks feed by sucking blood from the herbivores’ skin. The parasites then provide food for small birds known as oxpeckers. In turn, oxpeckers are food for goshawks. Which pyramid of numbers corresponds to this food chain?

Energy flow

What process is used to convert ammonia into nitrates?

Nutrient cycles

The cutting down of tropical rainforest trees has several effects. Which effect could result in global warming?

Effects of humans on ecosystems

The table gives the concentrations of four kinds of particle in two cells. Which particle can be transferred only by active transport between the cells in the direction stated?

Active transport

The concentration of dissolved oxygen in river water is recorded at equal intervals along the length of the river. Some untreated sewage is accidentally discharged into the river. Which graph shows how this pollution affects the dissolved oxygen in the water?

Effects of humans on ecosystems

Which category of food molecule includes nitrogen in its composition?

Biological molecules

Which test may be used to detect whether glucose is present?

Biological molecules

An indicator solution gives these colour changes: atmospheric carbon dioxide concentration: orange high carbon dioxide concentration: yellow low carbon dioxide concentration: purple. In the setup shown, both tubes contained orange indicator at the start of the experiment. What colours would the indicators be after three hours?

Photosynthesis

The diagram displays part of a leaf. Which numbers show cells in which both photosynthesis and gas exchange take place?

Leaf structure

Water passes from the soil into the atmosphere via a plant. The water enters the plant through the root hair cells and then moves into the root cortex. From the root cortex, where does the water move into?

Uptake and transport of water and ions

The lungs form part of the human gas exchange system. Breathing makes air move into the lungs and then out again.

Human gas exchange

Brown bread, produced from flour milled from whole wheat grains, contains starch and fibre.

Absorption and assimilation

Fig. 3.1 shows a photomicrograph of part of a woman’s capillary network. The feature labelled X is a red blood cell.

Blood

Certain plants are able to withstand severe dehydration for a prolonged period while dormant. When water becomes available, they begin to grow once more. These plants are adapted for life in deserts. Selaginella lepidophylla is one example of such a plant.

Cell structure and function

Bacillus subtilis is a bacterium species that is widely employed in biotechnology. It can be used to produce the protein lipase for industrial purposes.

Biotechnology

A narrow beam of intense light is directed into a human eye for two seconds. A comparable beam of light is directed at one side of the tip of a plant stem for several days.

Mammalian nervous system

Fig. 1.1 presents two cells taken from a plant leaf and viewed with a light microscope.

Cell structure and function

Organisms can be sorted into groups by the features they have in common.

Concept and use of a classification system

Use terms from the list to complete Table 3.1 by matching each description with the correct term.

DNA

Identify the structures marked P, Q and R in Fig. 4.1.

Urinary system

State which type of reproduction is used to grow pineapple plants in this way.

Asexual and sexual reproduction

Calculate the total mass of sulfur present in the fertiliser solution made by the gardener.

Mineral nutrition

Calculate the estimated total mass of plastic pollution that entered the ocean in 2020.

Effects of humans on ecosystems

Respiration, which releases energy from food in living organisms, can be represented by the equation below: glucose + oxygen → carbon dioxide + water A student investigated the rate at which oxygen was taken in for respiration by some small animals. The apparatus shown in Fig. 1.1 was used. The apparatus was sealed by closing the clip so that any change in the volume of gases in the test-tube and capillary tube caused the coloured liquid drop to move. The speed at which the coloured liquid drop moves is linked to the rate of oxygen uptake by the small animals. When the small animals in the test-tube respire, they take in oxygen and give out carbon dioxide.

Aerobic respiration

Fig. 2.1 contains four arthropods.

Concept and use of a classification system

A student carried out an investigation into the effect of exercise on their heart rate. The student found their heart rate at rest. They did this by sitting down, counting the number of heartbeats in 15 seconds, and then multiplying this to obtain the number in 60 seconds. The student then exercised for 10 minutes. After 10 minutes, the student stopped exercising and measured their heart rate for the 3 minutes after stopping. Table 3.1 shows some of their results.

Heart

A student carried out an investigation into the flower’s structure and nutrient content. Fig. 1.1 shows the flower. Some petals have been removed so that the internal arrangement can be seen clearly.

Sexual reproduction in plants

A student studied how many plants were growing on a school field. This was carried out by looking at small parts of the field with a square frame that measured 0.5 m \times 0.5 m. Fig. 2.1 displays the plants in one of these 0.5 m \times 0.5 m samples.

Ecosystems and biodiversity

Plants may be supplied with fertiliser to support their growth. Some students were given germinated seeds of the same species in several shallow dishes together with a 10% fertiliser solution. One dish is illustrated in Fig. 3.1. The students could use any other ordinary laboratory apparatus.

Mineral nutrition