IGCSE Biology 0610/11 May/June 2025 Past Paper with Answers

Question 1

A seed is planted in soil and watered. Over the following days the seed germinates: a root grows downwards into the soil, a shoot grows upwards towards the light, and the young seedling steadily increases in size. Which characteristics of living organisms are shown by this sequence of changes?

1. growth and sensitivity
2. growth only
3. nutrition and reproduction
4. reproduction and sensitivity

Question 2

Living organisms are named using the binomial system, which gives each organism a two-part scientific name. The scientific name for humans is Homo sapiens. Which statement correctly describes the two parts of this name?

1. Homo is the genus and sapiens is the species.
2. Homo is the genus and sapiens is the kingdom.
3. Homo is the species and sapiens is the genus.
4. Homo is the species and sapiens is the kingdom.

Question 3

Four features are used to describe a group of vertebrates: whether they maintain a constant body temperature, whether their eggs are covered in jelly, whether external ears are present, and whether scales are present. Which option correctly describes fish?

1. Fish do not maintain a constant body temperature, their eggs are covered in jelly, they have no external ears, and they have scales.
2. Fish maintain a constant body temperature, their eggs are not covered in jelly, they have external ears, and they have no scales.
3. Fish maintain a constant body temperature, their eggs are covered in jelly, they have no external ears, and they have scales.
4. Fish do not maintain a constant body temperature, their eggs are not covered in jelly, they have external ears, and they have no scales.

Question 4 · Answer A

Step 1: Red blood cells contain the red pigment haemoglobin, which binds to oxygen. Step 2: They are adapted with a biconcave shape and no nucleus to carry as much oxygen as possible. Step 3: So the red blood cell transports oxygen.

Question 5 · Answer A

Step 1: The tough layer outside the cell membrane is the cell wall, made of cellulose. Step 2: The cell wall gives the plant cell strength and support and stops it bursting. Step 3: Controlling entry and exit is the membrane, photosynthesis is in chloroplasts, and protein synthesis is at the ribosomes.

Question 6 · Answer A

Step 1: Drawing length = actual length multiplied by magnification. Step 2: Student 2 gives 0.125 multiplied by 300 = 37.5 mm; student 1 gives 18 mm; student 3 gives 33.75 mm; student 4 gives 35 mm. Step 3: The largest value is 37.5 mm, so student 2 produced the longest drawing.

Question 7 · Answer A

Step 1: Respiration produces carbon dioxide, so the substance is carbon dioxide. Step 2: A substance diffuses from where it is more concentrated to where it is less concentrated. Step 3: To move from the blood vessel into the alveolus the carbon dioxide must be at a high concentration in the blood and a low concentration in the alveolus.

Question 8 · Answer A

Step 1: Water enters cells by osmosis when the surroundings are more dilute (have more water) than the cell contents. Step 2: Distilled water is the most dilute surrounding, so water moves into the potato fastest and its mass increases the most. Step 3: The sugar solutions are more concentrated, so less water enters or water is lost, and the piece in air dries out.

Question 9 · Answer A

Step 1: Starch is a large carbohydrate that contains only carbon, hydrogen and oxygen. Step 2: Starch is built from many glucose molecules joined together. Step 3: Fats contain glycerol and fatty acids, and only proteins contain nitrogen, so the correct match is starch made from glucose.

Question 10 · Answer A

Step 1: DCPIP is a blue dye that is decolourised (turned colourless) by vitamin C. Step 2: So a sample that turns blue DCPIP colourless contains vitamin C. Step 3: Starch is tested with iodine, protein with biuret solution, and fat with the ethanol emulsion test.

Question 11 · Answer A

Step 1: Enzyme X is active only in acidic conditions around pH 2 and is inactive by pH 5. Step 2: Enzymes Y and Z both work in alkaline conditions and both still show activity at pH 8. Step 3: X is not active at pH 7, and neither Y nor Z is active at pH 4, so only "Y and Z are both active at pH 8" is correct.

Question 12 · Answer A

Step 1: Photosynthesis uses carbon dioxide and water as its raw materials. Step 2: It produces glucose and oxygen. Step 3: So the substances taken in (1 and 2) are water and carbon dioxide, and those given out (3 and 4) are glucose and oxygen.

Question 13 · Answer A

Step 1: The palisade mesophyll is the upper layer of tall cells just below the upper surface, so region 2 is the palisade mesophyll. Step 2: The spongy mesophyll lies below the palisade layer, so region 3 is the spongy mesophyll. Step 3: The vein, made of xylem and phloem, runs through the middle, so region 1 is the vascular bundle.

Question 14 · Answer A

Step 1: Iron is used to make haemoglobin in red blood cells. Step 2: Haemoglobin carries oxygen, so without enough iron the body cannot make enough red blood cells, causing anaemia. Step 3: Rickets is caused by lack of vitamin D, scurvy by lack of vitamin C, and teeth are strengthened by calcium and fluoride.

Question 15 · Answer A

Step 1: Egestion is the passing out of material that was never digested or absorbed. Step 2: This undigested material forms faeces in the large intestine and is stored in the rectum. Step 3: It leaves the body through the anus, so egestion takes place at the end of the large intestine.

Question 16 · Answer A

Step 1: Incisors are the chisel-shaped front teeth, so the front lower tooth W is an incisor. Step 2: Molars are the large grinding teeth at the very back, so X is a molar, and premolars sit just in front of the molars, so Y is a premolar. Step 3: Canines are the pointed teeth near the front corners, so Z is a canine.

Question 17 · Answer A

Step 1: Protease enzymes digest proteins into amino acids. Step 2: The protease in the stomach is made by the stomach lining, so protease is produced in the stomach and forms amino acids. Step 3: Amylase is made in the salivary glands and digests starch into simple reducing sugars, so the other rows mix up the enzymes and products.

Question 18 · Answer A

Step 1: Xylem vessels carry water and dissolved minerals up from the roots through the stem. Step 2: The red dye is carried up inside the xylem, so the xylem becomes stained red. Step 3: Phloem carries sugars, the cuticle is a waxy outer layer, and a style is part of a flower, so none of these carry the water.

Question 19 · Answer A

Step 1: The renal vein carries blood away from a kidney back towards the heart, which matches the vessel in the correct option. Step 2: The vessel from the heart to the lungs is the pulmonary artery, not the coronary artery, and the vessel from the lungs to the heart is the pulmonary vein, not the pulmonary artery. Step 3: The vessel carrying blood from the body into the heart is the vena cava, not the aorta, so only the renal vein is named correctly.

Question 20 · Answer A

Step 1: The body uses oxygen and releases carbon dioxide, so expired air contains more carbon dioxide and less oxygen than inspired air. Step 2: Therefore carbon dioxide is lower in inspired air, making statement 2 correct, and oxygen is higher in inspired air, making statement 3 correct. Step 3: So statements 2 and 3 are the correct pair.

Question 21 · Answer A

Step 1: Germinating seeds need water to activate their enzymes and oxygen for aerobic respiration to release energy. Step 2: The chemical in the tube absorbs the carbon dioxide the seeds give out, so carbon dioxide is not a substance the seeds need. Step 3: Chlorophyll is only needed later for photosynthesis once leaves form, so the seeds need oxygen and water.

Question 22 · Answer A

Step 1: Anaerobic respiration in yeast is called fermentation. Step 2: Yeast break down glucose without oxygen to produce alcohol (ethanol) and carbon dioxide. Step 3: Lactic acid is the product in human muscle, while oxygen and water are not products of anaerobic respiration.

Question 23 · Answer A

Step 1: Urea is a waste product made in the liver and carried in the blood. Step 2: The kidneys filter urea out of the blood to form urine. Step 3: The bladder only stores urine, the lungs excrete carbon dioxide, and the stomach is part of digestion.

Question 24 · Answer A

Step 1: Direct contact means the pathogen passes straight from one person to another, for example through their blood. Step 2: Contaminated blood spreads pathogens by direct contact between people. Step 3: Contaminated air, food and surfaces are indirect routes, because the pathogen passes through the environment before reaching a new person.

Question 25 · Answer A

Step 1: The sensory neurone carries impulses from the receptor towards the spinal cord, so the neurone joined to the skin receptor, P, is the sensory neurone. Step 2: The relay neurone lies inside the spinal cord and links the sensory and motor neurones, so Q is the relay neurone. Step 3: Neurone R, joined to the muscle, is the motor neurone.

Question 26 · Answer A

Step 1: The pancreas releases insulin into the blood. Step 2: Insulin lowers blood glucose concentration when it rises too high. Step 3: Adrenaline comes from the adrenal glands, oestrogen from the ovaries, and testosterone from the testes.

Question 27 · Answer A

Step 1: Roots grow towards gravity (positive gravitropism), so statement 2 is correct and statement 1 is wrong. Step 2: Shoots grow towards light (positive phototropism), so statement 4 is correct and statement 3 is wrong. Step 3: So the correct examples are statements 2 and 4.

Question 28 · Answer A

Step 1: Antibiotics are medicines that kill bacteria or stop them growing. Step 2: They have no effect on viruses, which is why they cannot treat viral infections such as colds. Step 3: Antibiotics are manufactured as drugs; they are not produced by platelets or white blood cells.

Question 29 · Answer A

Step 1: Sexual reproduction involves the fusion of the nuclei of two gametes at fertilisation, so statement 4 is correct. Step 2: This mixing of genetic material from two parents produces offspring that are genetically different, so statement 1 is correct. Step 3: Sexual reproduction occurs in plants as well as animals and does not make identical offspring, so statements 2 and 3 are wrong.

Question 30 · Answer A

Step 1: The menstrual cycle is counted from the first day of menstruation, a period. Step 2: At the start of the cycle the thickened uterus lining breaks down and is lost as blood through the vagina. Step 3: The lining only repairs, thickens and grows new blood vessels later in the cycle, and implantation happens only if an egg is fertilised.

Question 31 · Answer A

Step 1: HIV is spread mainly through body fluids, including during unprotected sex. Step 2: Using condoms acts as a barrier that stops the exchange of these fluids, reducing transmission. Step 3: Clean water, hygienic food and sewage treatment prevent diseases spread by water or food, not HIV.

Question 32 · Answer A

Step 1: A gene can exist in different versions, for example a version for brown eyes and a version for blue eyes. Step 2: These alternative forms of the same gene are called alleles. Step 3: A chromosome is a thread of DNA carrying many genes, a genotype is the alleles an organism has, and a phenotype is its observable features.

Question 33 · Answer A

Step 1: There are only two distinct types of ear wax with no values in between, which is discontinuous variation. Step 2: This feature is determined by genes alone, with no environmental effect. Step 3: So it is discontinuous variation controlled by genes only.

Question 34 · Answer A

Step 1: Natural selection acts when individuals vary and some are better suited to their surroundings. Step 2: Giraffes with longer necks could reach more food, so they were better adapted and more likely to survive and reproduce. Step 3: Breeding chosen animals is artificial selection, and with no competition or no trees there would be no advantage to a long neck.

Question 35 · Answer A

Step 1: Alpine plants have only a short snow-free season in which to reproduce. Step 2: To complete reproduction in this short time they must both flower and produce seeds quickly. Step 3: Flowering or seeding slowly would not leave enough time before the snow returns.

Question 36 · Answer A

Step 1: A secondary consumer eats primary consumers, which are the herbivores. Step 2: The larvae are primary consumers because they eat algae, and the diving beetle eats these larvae, so the diving beetle is a secondary consumer. Step 3: The blackfly larva is a primary consumer, while the frog and pike are higher-level consumers that eat secondary consumers.

Question 37 · Answer A

Step 1: Removing the carnivores means fewer herbivores are eaten, so the number of herbivores increases at first. Step 2: As the herbivores become more numerous they begin to run short of food and space, so the population stops rising and levels off. Step 3: So the number increases and then levels off, rather than falling, staying the same, or rising without limit.

Question 38 · Answer A

Step 1: Agricultural machinery lets farmers work larger areas of land efficiently, so statement 1 is correct. Step 2: Selective breeding produces livestock that give more meat or milk, so statement 3 is correct. Step 3: Herbicides kill weeds and so reduce competition with crops rather than increase it, so statement 2 is wrong.

Question 39 · Answer A

Step 1: Conservation aims to protect species and stop their numbers falling further. Step 2: Seed banks store seeds so that plant species can be grown again in the future, which helps to conserve them. Step 3: Monocultures, overharvesting and reducing biodiversity all harm species rather than conserve them.

Question 40 · Answer A

Step 1: Useful bacteria for biotechnology should reproduce quickly so that large numbers build up fast. Step 2: They should also have a high ability to make complex molecules, which are the useful products. Step 3: Type 4 has both the fastest reproduction rate, 3.0 divisions per hour, and a high ability to make complex molecules, so it is the most useful.