May/June 2018

The diagram illustrates a palisade cell. Which structure is the location of photosynthesis?

Photosynthesis

The villi in the intestinal wall increase the surface area of the small intestine. In what way does this larger surface area aid the absorption of digested materials?

Absorption and assimilation

The photograph displays the cells of a vascular bundle from a stem, viewed through a microscope. What is tissue G, and what is its function?

Specialised cells, tissues and organs

When plants grow in soil that is saturated with water, their roots do not receive enough oxygen. How will the functions of root hairs be affected under these conditions?

Uptake and transport of water and ions

Which blood vessel carries blood into the liver?

Blood vessels

The diagram illustrates a person's blood pressure at rest as blood leaves the heart and then moves through arteries followed by capillaries. Which line indicates the pressure of blood while it travels through veins before it returns to the heart?

Blood vessels

The diagram shows a cross-section of part of a vein. What are the first organs reached in directions 1 and 2?

Blood vessels

Which word equation represents the respiration taking place in an athlete’s muscle cells before a race begins?

Aerobic respiration

Yeast is used in bread-making. Why is there little or no alcohol in the bread?

Anaerobic respiration

The table illustrates the effect of exercise on breathing rate and depth. What is the increase in the volume of air exchanged each minute after exercise, compared with at rest?

Human gas exchange

The diagram illustrates the operation of a kidney dialysis machine. Every shape stands for a molecule present in blood or dialysis fluid. Which shape represents urea?

Urinary system

Which process requires energy released by respiration?

Active transport

The diagram illustrates some of the structures visible in a cross-section of human skin. What function does structure X perform?

Specialised cells, tissues and organs

The diagram shows a cross-section of an eye. Which part acts as the receptor for the stimulus that causes the pupil to change size?

Mammalian sense organs

The diagram illustrates the brain in vertical section. Which structure coordinates the menstrual cycle?

Mammalian hormones

Which one of these is a reflex action?

Mammalian nervous system

Which bones join together at the elbow joint, and what type of movement do they permit?

Specialised cells, tissues and organs

The diagram illustrates the proportions of injecting and non-injecting drug users who have HIV/AIDS in one specific region of the world. What explains the difference between these two groups of drug users?

Disease

Penicillin is made by the fungus Penicillium. The stages involved are given below. 1 Corn and yeast are added to the fungus. 2 Penicillin is extracted. 3 Penicillin is secreted by the fungus. 4 The product is filtered. What is the order of these stages?

Biotechnology

Which table displays the characteristics of bacteria, fungi and viruses?

Features of organisms

The graph illustrates how the populations of plant plankton and animal plankton in a lake change over time. Consider the following statement in relation to the data shown on the graph. ‘Changes in the population of animal plankton occur later than similar changes in plant plankton because the animals eat the plants.’ Which category does the statement belong to?

Energy flow

Which sequence constitutes a food chain?

Energy flow

A plant is growing in fertile soil that is well supplied with water. It takes in nitrate ions by active transport and absorbs water by osmosis. How do the concentrations of nitrate ions and water in the plant’s roots compare with the concentrations in the soil?

Active transport

Which part of the carbon cycle relies on bacteria and fungi being present in the soil?

Nutrient cycles

Which term accurately identifies the malarial pathogen?

Concept and use of a classification system

Which two air pollutants are responsible for acid rain?

Effects of humans on ecosystems

The diagram illustrates the chromosomes in a cell. Which diagram shows the outcome of one division of the cell by mitosis?

Nuclear division

The diagram illustrates the stigma, style and ovary of a flower. In which part does fertilisation occur?

Sexual reproduction in plants

In which section of the human female reproductive system does a zygote begin dividing to produce a ball of cells?

Sexual reproduction in humans

What is the most effective method of preventing the spread of the human immunodeficiency virus (HIV)?

Disease

The diagram illustrates two chromosomes from one cell. A gene is located at the point marked P. In a heterozygous individual, what would be present at the corresponding position labelled Q?

Inheritance

Which human characteristics display continuous variation and which show discontinuous variation?

Variation

Which statements concerning natural selection are correct?

Selection

During an enzyme reaction, where is the active site found, and where are the lock and key?

Enzyme action

Which statements about genetically engineered plants indicate possible benefits?

Genetic modification

The diagram shows a cross-section of part of a leaf viewed under a microscope. In which part does translocation (movement of sucrose and amino acids) take place?

Transpiration and translocation

The diagrams illustrate an experiment used to determine the rate of photosynthesis in an aquatic plant under different conditions. Which plant gives the greatest number of bubbles per minute?

Photosynthesis

A student cultivates seedlings in four separate test-tubes. Tube W has every mineral ion required for healthy plant growth. The diagram illustrates what these seedlings look like after two weeks. What are present in tubes X, Y and Z?

Mineral nutrition

Which substance is composed of amino acids?

Biological molecules

At which point does bile enter the alimentary canal?

Human digestive system

Which characteristic shows that a root cell comes from a plant rather than an animal?

Cell structure and function

The diagram shows a structure that is part of the wall of the alimentary canal. In what section of the alimentary canal can this structure be found?

Human digestive system

The paragraph below explains how water is absorbed by roots. Root hair cells have ......1...... cell walls, which help them take in water. The cytoplasm in the cell has a ......2...... water potential than the soil water, so water enters the root hair cell from the soil by ......3...... . Which words correctly fill spaces 1, 2 and 3?

Diffusion and osmosis

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

Transpiration and translocation

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

Heart

The diagram illustrates the blood pressure of a person who is resting, starting as blood leaves the heart and then moves through arteries before reaching capillaries. Which line represents the pressure of blood as it travels through veins on the way back to the heart?

Blood vessels

The diagram illustrates a cross-section of part of a vein. Which organs would be encountered first in directions 1 and 2?

Blood vessels

Which chemicals are formed during anaerobic respiration in yeast cells?

Anaerobic respiration

Two individuals with the same body mass each carry out the same amount of exercise. One individual is healthy, whereas the other has emphysema. The rate at which oxygen enters each person's blood in the lungs is measured. The findings are given in the table (oxygen entering blood in $\text{cm}^3$ per minute: healthy person 22, person with emphysema 12). Which statement explains these results?

Human gas exchange

The table compares how exercise changes the rate and depth of breathing. At rest: breathing rate 12 breaths per minute, volume of each breath $500\,\text{cm}^3$. After exercise: breathing rate 24 breaths per minute, volume of each breath $1000\,\text{cm}^3$. What is the increase in the volume of air exchanged per minute after exercise, compared with at rest?

Human gas exchange

The diagram illustrates the human urinary system. Which part is the urethra?

Urinary system

Which process requires energy from respiration?

Respiration

The diagram shows some of the structures visible in a section of human skin. What is the function of structure X?

Specialised cells, tissues and organs

The diagram illustrates a horizontal section through a human eye. Which part contains receptor cells that are sensitive to light?

Mammalian sense organs

The diagram illustrates the outside view of a brain. Which part of the brain is responsible for thinking and making decisions?

Mammalian nervous system

In diabetes, glucose is found in the urine. In what way does insulin stop this from happening?

Blood glucose control

Which bones come together at the elbow joint, and what type of movement do they permit?

Specialised cells, tissues and organs

What are some consequences of using heroin?

Mammalian nervous system

Antibiotics, such as penicillin, are manufactured on a large scale in fermenters. Which substance is not required for the production of penicillin in this way?

Antibiotics

Some young plants were planted in the soil and developed normally for a few weeks. After that, they started to show symptoms of disease. Samples from the infected leaves were viewed with a microscope. Which observations of the organism responsible for the disease indicate that it may be a fungus?

Features of organisms

The graph illustrates how the populations of plant and animal plankton in a lake change over time. With reference to the information shown on the graph, consider this statement: 'Population changes in animal plankton lag behind similar changes in plant plankton because the animals feed on the plants.' Which category does this statement belong to?

Energy flow

A food chain is illustrated. grain $$ insects $$ small birds $$ owls $$ lice What would the pyramid of numbers be for this food chain?

Energy flow

The diagram illustrates the outcome of an experiment. After three hours, the liquid in the glass tube had risen to point $X$. In a second experiment, what change could be made so that the liquid rises above $X$?

Transpiration and translocation

In the carbon cycle, which process puts carbon back into a food chain?

Nutrient cycles

Which measure will not assist in reducing the transmission of the malarial vector within the human population?

Disease

Which alteration would cause biodiversity in an area to rise?

Ecosystems and biodiversity

The diagram illustrates the chromosomes in a cell. Which diagram shows the result of one division of the cell by mitosis?

Nuclear division

The diagram illustrates a cross-section of a flower. Which statement is true?

Sexual reproduction in plants

The diagram depicts a baby just before birth. Which labelled structures are the cervix and uterus?

Sexual reproduction in humans

A person’s basal body temperature is the body temperature measured as soon as they wake in the morning. In women, a rise in blood progesterone concentration leads to a slight increase in basal body temperature. The graph shows the basal body temperature of one woman across a 28-day period. On which day did ovulation take place?

Sexual reproduction in humans

The diagram illustrates two chromosomes taken from the same cell. A gene is located at the point marked P. In a heterozygous individual, what would be present at the corresponding position marked Q?

Inheritance

The table presents the differences in foot length among several students. Which row identifies this type of variation and gives its cause?

Variation

The fruit colour in tomato plants is controlled by alleles of the same gene. A tomato plant with red fruit was crossed with a tomato plant with yellow fruit. Among the offspring, 26 plants produced red fruit and 24 produced yellow fruit. Three explanations were proposed. Which explanations are correct?

Inheritance

During enzyme action, where is the active site located, and what is meant by the lock and key?

Enzyme action

Diabetes can be managed by using insulin made through genetic engineering. In what place is this insulin made?

Mammalian hormones

The diagram shows a microscope view of a cross-section through part of a leaf. In which part does translocation (movement of sucrose and amino acids) take place?

Transpiration and translocation

The diagrams illustrate an experiment used to determine the rate of photosynthesis in an aquatic plant under different conditions. Which plant is producing the highest number of bubbles each minute?

Photosynthesis

A student is growing seedlings in four separate test-tubes. Tube W has every mineral ion required for healthy plant growth. The diagram illustrates how these seedlings look after two weeks. What are contained in tubes X, Y and Z?

Mineral nutrition

What kind of molecule is used to make glycogen?

Biological molecules

Which factor is most likely to lead to rickets?

Diet

The diagram presents a food web in a pond.

Energy flow

The diagram depicts a male human gamete.

Sexual reproduction in humans

The diagram illustrates the fruit of a plant.

Sexual reproduction in plants

The diagram illustrates a human heart together with the blood vessels connected to it.

Heart

Describe the principal characteristics of a virus.

Immunity

This diagram presents an enlarged transverse section of a leaf.

Transpiration and translocation

Define what is meant by allele.

Inheritance

Describe one simple reflex action and explain why this action is important to the body.

Mammalian nervous system

Explain what is meant by control through negative feedback.

Temperature control

The diagrams depict the bud of an insect-pollinated flower together with a magnified transverse section of that same flower bud. The transverse section was cut at the point marked by the dotted line.

Sexual reproduction in plants

The heart is shown in the diagram. The vessel marked F can be seen narrowing, as illustrated.

Heart

The table illustrates how the thickness of the eye lens varies when focusing on objects at different distances from the front of the eye.

Mammalian sense organs

The graph illustrates how crop yield (amount harvested) is affected when fertilisers containing nitrogen are used.

Mineral nutrition

The diagram presents a cross-section of the human body split into regions P, Q, R and S.

Specialised cells, tissues and organs

The diagram shows a magnified transverse section of a leaf.

Leaf structure

Describe the cause of each of these conditions: Down’s syndrome; sickle cell anaemia.

Inheritance

Outline how a named type of microorganism is involved in the production of each of the following products: yoghurt; bread.

Biotechnology

Explain why most food consumed by a human needs to be digested.

Human digestive system