May/June 2021

Which structures occur in plant cells but are absent from animal cells?

Cell structure and function

Which of the following is not an example of assimilation?

Absorption and assimilation

What characteristic of a root hair cell enables it to absorb ions from water in the soil?

Specialised cells, tissues and organs

The diagram illustrates the route taken by water molecules through part of a leaf, viewed in transverse section with a microscope. At which point does water evaporate?

Transpiration and translocation

Which row gives the roles of the blood components?

Blood

The diagram shows a cross-section of the human heart. What is the condition of the valves when chambers X and Y are contracting?

Heart

The diagram shows the blood flow to the liver and the kidneys. Which vessels carry blood with the greatest and the smallest concentrations of urea?

Excretion

What is not a characteristic of aerobic respiration?

Aerobic respiration

During an investigation, scientists exposed plant roots to a chemical that prevents aerobic respiration. They found that, after the exposure, the plant roots took up nitrate ions at a slower rate. Which statement best explains this result?

Active transport

Why is oxygen taken up by the blood in the lungs?

Human gas exchange

The diagram shows structures in a human that produce and store urine. Liquids move through tubes X, Y and Z in the directions indicated by the arrows. Which statement about the amount of liquid passing through Y in one day is correct?

Urinary system

A sample of plant tissue is moved from a beaker containing water into a concentrated sugar solution. Which row shows what happens?

Diffusion and osmosis

The diagram illustrates the homeostatic regulation of body temperature. What are the corrective mechanisms P and Q, and the coordinator R?

Temperature control

The diagram shows a cross-section of the brain. Which region of the brain releases hormones?

Mammalian hormones

What changes take place in the eye when a distant object is being viewed?

Mammalian sense organs

The diagram illustrates three locations, X, Y and Z, where a drug stops nerve impulses. Which person in the list below would move their leg after being pricked with a pin, but would not feel the pinprick?

Mammalian nervous system

Which two bones together make a hinge joint in the forelimb?

Specialised cells, tissues and organs

What effects does consuming a large amount of alcohol have on the human body?

Mammalian nervous system

The diagram illustrates the structure of a bacterium. How does this differ from a fungus cell?

Cell structure and function

Which product is manufactured using bacteria?

Biotechnology

These processes take place in living organisms within a food chain. Which of them would cause energy to be lost from a food chain?

Energy flow

Which of the statements are correct?

Cell structure and function

Which of these statements about active transport are correct?

Active transport

The diagram illustrates the transfer of carbon in the carbon cycle, in gigatonnes per year. How many gigatonnes of carbon are transferred by respiration each year?

Nutrient cycles

What functions do the female mosquito and the malarial pathogen each have in the transmission of malaria?

Disease

Which human activity will contribute most to global warming?

Effects of humans on ecosystems

The diagram illustrates two onion plants. From the information shown in the diagram, which statement about these onion plants is correct?

Diffusion and osmosis

Six bean seeds were left to soak in cold water. Three of these were then boiled and allowed to cool. The boiled seeds and the unboiled seeds were cut into small pieces and placed on the top of agar jelly that contained starch. After two days, all the seeds were taken away and the jelly was tested using iodine solution. The diagram illustrates the outcome of the experiment. What is the explanation for the results with the non-boiled bean seeds?

Enzyme action

The diagram illustrates how blood from a human fetus flows near to the mother’s blood in the placenta. Which substances are found at X in greater concentrations than at Y?

Sexual reproduction in humans

Why are antibiotics unable to cure a person who has HIV infection?

Antibiotics

Chromosomes, DNA molecules and genes are inherited structures of different lengths. Which statement best explains how these pieces of inherited material are related?

DNA

Earlobes may either be joined to the cheek or free-standing (unattached). A single gene controls this feature. The allele for attached earlobes is recessive. The diagram illustrates the inheritance pattern of attached earlobes in one family. Which two individuals must be heterozygous for earlobe attachment?

Inheritance

Which of these statements about natural selection are correct?

Selection

Which statement correctly describes enzymes?

Enzyme action

Which characteristic of a cereal crop cannot be improved through selective breeding on its own?

Selection

An experiment was conducted to study how light intensity and carbon dioxide concentration affect the rate of photosynthesis. Which graph illustrates the findings of this experiment?

Photosynthesis

What is the role of the upper cuticle of a leaf?

Leaf structure

Plants growing in soil with a shortage of magnesium ions have poor growth. What is the cause of this poor growth?

Mineral nutrition

Which statement concerning diets is correct?

Diet

The diagram illustrates part of the human alimentary canal and the organs connected with it. Which row describes the functions of the parts shown in the diagram?

Human digestive system

Which row is right?

Features of organisms

The diagram illustrates part of the human alimentary canal and related organs. Which row gives the functions of the parts shown in the diagram?

Human digestive system

By what process does water enter root hair cells?

Diffusion and osmosis

The diagram illustrates the route taken by water molecules through a section of a leaf, viewed in transverse section under a microscope. At what point does the water evaporate?

Transpiration and translocation

Which row gives the functions of the blood components?

Blood

The diagram illustrates how the volume of blood in the left ventricle of a human heart varies over one heartbeat. During which stage is the left ventricle contracting?

Heart

The diagram shows the blood supply to the liver and kidneys. Which vessels carry blood with the highest and lowest urea concentrations?

Excretion

Which of the following statements is correct for aerobic respiration?

Aerobic respiration

The graph illustrates the concentration of substance $X$ in a person’s blood before, during, and after exercise. What is substance $X$?

Respiration

While exercising, a person breathes more deeply and more often. Which effect results from this?

Human gas exchange

The diagram illustrates parts of the human body that produce and store urine. Liquid flows through tubes X, Y and Z in the directions indicated by the arrows. Which statement about the volume of liquid passing through Y in one day is correct?

Urinary system

A piece of plant tissue is moved from a beaker containing water into a concentrated sugar solution. Which row shows what happens?

Diffusion and osmosis

Which reaction occurs if a person enters a cold environment?

Temperature control

The diagram illustrates the human brain. What is the name of the shaded area of the brain?

Mammalian nervous system

What changes occur in the eye to cause the pupil reflex in bright light?

Mammalian sense organs

The diagram indicates three positions, X, Y and Z, where a drug prevents nerve impulses from travelling. Which person below would move their leg when pricked with a pin, yet would not feel the pinprick?

Mammalian nervous system

The diagram illustrates how antagonistic muscles are arranged in the arm. Which row identifies the muscle action as the arm is straightened?

Specialised cells, tissues and organs

Electronic cigarettes are a substitute for cigarettes that makes it possible to inhale nicotine without the other substances present in cigarette smoke. Which effects of smoking cigarettes will also be effects of using electronic cigarettes?

Circulatory system

The diagram illustrates the structure of a bacterium. How is this different from a cell of a fungus?

Cell structure and function

Which microorganisms take part in the decomposition of dead plant material?

Nutrient cycles

Why is the flow of energy through an ecosystem described as non-cyclic?

Energy flow

A full food web is shown in the diagram. Which row gives examples of the organism types in this food web?

Energy flow

The statements below are about how substances move into and out of cells. 1 Energy from respiration is needed. 2 Energy from respiration is not needed. 3 The movement takes place down a concentration gradient. 4 The overall movement is from a region of higher concentration to a region of lower concentration. 5 The overall movement is from a region of lower concentration to a region of higher concentration. Which statements apply to active transport?

Active transport

The diagram illustrates part of the carbon cycle. What are X, Y and Z?

Nutrient cycles

Marine coastal areas contain a wide variety of plant and animal life. Which process would lead to a decrease in the biodiversity of these environments?

Ecosystems and biodiversity

Hardwood trees in tropical rainforests are often cut down for timber. After this, one fast-growing crop, such as palm oil, is cultivated on that same area of land. What effect will clearing the rainforest have on the environment?

Effects of humans on ecosystems

The diagram shows part of a Bryophyllum plant. Which option gives the clearest description of the way the new plants are formed?

Asexual and sexual reproduction

Six bean seeds were left to soak in cold water. Three of them were boiled and then allowed to cool. The boiled seeds and the unboiled seeds were cut into pieces and then put on the surface of agar jelly that contained starch. After two days, all the seeds were taken out and the jelly was tested with iodine solution. The diagram shows the outcome of the experiment. What is the explanation for the results with the non-boiled bean seeds?

Enzyme action

The diagram illustrates the way the blood of a human fetus flows close to the mother’s blood in the placenta. Which substances are found at X in greater concentration than at Y?

Sexual reproduction in humans

The table lists four methods by which diseases can spread from one person to another. Which row indicates the methods by which HIV can be transmitted?

Disease

Which sex chromosomes does every sperm cell contain?

Inheritance

Earlobes may be either attached to the cheek or ‘free’ (unattached). One gene controls this feature. The allele that causes attached earlobes is recessive. The diagram illustrates how attached earlobes are inherited in one family. Which two individuals have to be heterozygous for earlobe attachment?

Inheritance

Which of the following statements about natural selection are correct?

Selection

Which word is used for an enzyme whose active site is altered by high temperature?

Effects of temperature and pH

Several steps in the manufacture of human insulin are shown below. 1. Genetically modified $E.\ coli$ bacteria are cultured in large fermenters. 2. The gene for human insulin is placed into the DNA of a bacterium named $E.\ coli$. 3. The gene for human insulin is taken from human pancreas cells. 4. Human insulin is then removed and purified. What is the correct order of these stages?

Genetic modification

Hydrogencarbonate indicator alters colour depending on the amount of carbon dioxide present. The table indicates the way hydrogencarbonate indicator changes colour. Four test-tubes were arranged under different conditions. The colour of hydrogencarbonate indicator in each test-tube at the beginning of the experiment and after 1 hour is also shown. Which test-tube indicates that the rates of photosynthesis and respiration are equal?

Photosynthesis

Which term is used to describe the upper cuticle of a leaf?

Leaf structure

Insufficient amounts of some mineral ions reduce the growth of young plants. Which effects result from a shortage of magnesium ions and a shortage of nitrate ions?

Mineral nutrition

The graph displays several of the nutrients present in peanuts. A student carried out four food tests on peanuts. Which row gives the results?

Biological molecules

Which row identifies factors that could lead to famine?

Effects of humans on ecosystems

The diagram depicts a root hair cell from a lemon tree together with some soil particles.

Uptake and transport of water and ions

An eye doctor is visited for an eye test, and a diagram of an eye is shown on the wall in the doctor’s room.

Mammalian sense organs

A sycamore tree functions as a producer in many food chains in a forest ecosystem.

Energy flow

The diagram illustrates part of the human alimentary canal together with its associated organs.

Human digestive system

A farmer is weeding her crop with a tool known as a mattock.

Specialised cells, tissues and organs

Yoghurt is a product made from milk.

Biotechnology

In liver cells, excess amino acids are broken down to make urea molecules.

Nutrient cycles

Rice, maize and wheat plants provide the principal carbohydrate supply for over 60% of the human population.

Photosynthesis

Describe the process of inhalation, using the rib cage and diaphragm, so that air reaches the alveoli.

Human gas exchange

The diagram displays the teeth in the lower jaw of a human being.

Disease

The diagram illustrates how the main blood vessels are arranged in the human circulatory system. The arrows indicate the direction in which blood flows through each vessel.

Blood vessels

The illustration depicts an elm tree.

Disease

Cardiopulmonary resuscitation (CPR) is a first aid technique.

Human gas exchange

The diagram illustrates villi in the small intestine.

Absorption and assimilation

The diagram illustrates the human life cycle.

Nuclear division

The diagram depicts the structures involved in a reflex action that makes a person’s hand move away from a sharp object.

Mammalian nervous system

State the functions carried out by the human liver and explain why each function is important to a person.

Excretion

Describe the large-scale production of an antibiotic that is named and explain why each stage of the process is important.

Antibiotics