Biology 0610/21 October/November 2025: question paper and mark scheme

Question

The diagrams show a plant at the start of an experiment, and the same plant two weeks later. start of the experiment after two weeks light from one side Which characteristics of living organisms are demonstrated by this experiment? A excretion and growth B excretion and reproduction C growth and sensitivity D sensitivity and reproduction

Question

What can be used to classify organisms? A the number of bases in DNA B the number of different types of bases in DNA C the sequence of bases in DNA D the sequence of bases in one protein

Question

The diagram shows a single cell from an organism called Spirogyra. cytoplasm chloroplast cell wall vacuole strand of nucleus cytoplasm Which features does Spirogyra share with plant cells? cell wall chloroplast cytoplasm nucleus vacuole A yes yes yes yes yes B yes yes no no yes C yes no yes yes no D no yes yes no yes

Question

The diagram shows an image of a chloroplast. The image is 5 cm long. The actual length of the chloroplast is 5 μm. What is the magnification of the image? A ×10 B ×1000 C ×10 000 D ×100 000

Question

A potato was used as a source of plant tissue. Four potato sticks of identical size were cut from the same potato. At the start of the investigation, each potato stick was 10 squares long. The potato sticks were put into four separate Petri dishes. Each Petri dish contained a different concentration of sugar solution. The diagram shows the four Petri dishes after 24 hours. Which dish contains a sugar solution that has a higher water potential than the potato tissue? A B Petri dish potato stick C D

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Which row shows correct statements about active transport? requires a partially direction of movement permeable membrane A down a concentration gradient no B down a concentration gradient yes C against a concentration gradient no D against a concentration gradient yes

Question

The graph shows the effect of temperature on an enzyme-controlled reaction. rate of reaction 0 10 20 30 40 50 60 temperature / °C Which statement describes the effect of temperature on this reaction? A As the temperature increases to 25 °C, the reaction speeds up. B Between 10 °C and 20 °C, the enzyme denatures. C Between 35 °C and 45 °C, frequency of effective collisions increases. D The optimum temperature for this reaction is 40 °C.

Question

The graph shows the rate of photosynthesis of a plant in full sunlight in different concentrations of carbon dioxide. All other factors were kept constant. rate of photosynthesis 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 percentage carbon dioxide concentration What limits the rate of photosynthesis at 0.02% carbon dioxide concentration? A carbon dioxide concentration B humidity C light intensity D temperature

Question

A student wrote some statements about the palisade mesophyll and spongy mesophyll tissues. 1 The spongy mesophyll tissue is near the stomata for gas exchange. 2 Only palisade mesophyll cells have chloroplasts for photosynthesis. 3 Palisade cells are closely packed but there are air spaces in the spongy mesophyll tissue. Which statements are correct descriptions of the two tissues? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

What is a role of bile? A It contains enzymes that digest starch. B It emulsifies fats, increasing their surface area. C It kills bacteria in food. D It provides the optimum pH for pepsin activity.

Question

Where in the alimentary canal is the enzyme trypsin found and what are the products of the reaction trypsin catalyses? where trypsin products is found A duodenum amino acids B duodenum fatty acids C ileum proteins D stomach amino acids

Question

What is a structural feature of xylem vessels? A contain many mitochondria B made up of cells joined end to end C presence of cross walls D thin walls

Question

During the growing season, tomato plants produce flowers and fruits. Which parts of a growing tomato plant are sources, and which parts are sinks? flowers fruits leaves A sink sink source B sink source sink C source sink source D source source sink

Question

Which statements are correct descriptions of methods of preventing pathogens from entering the body? 1 Fibrin is converted to fibrinogen to form a mesh. 2 Phagocytes produce antibodies. 3 Platelets clot blood. 4 Lymphocytes engulf pathogens. A 1, 3 and 4 B 1 and 3 only C 2 and 4 D 3 only

Question

Which statement describes a double circulatory system? A Blood goes through the lungs twice every time it goes round the body. B Blood goes through the kidneys twice every time it goes round the body. C Blood goes through the heart twice every time it goes round the body. D Blood goes through the brain twice every time it goes round the body.

Question

Three statements about immunity are listed. 1 Specific antibodies are produced in response to specific antigens. 2 Pathogens have specific antigens. 3 A vaccination stimulates an immune response. Which statements are correct? A 1, 2 and 3 B 1 and 3 only C 1 only D 2 and 3 only

Question

Which muscles in the breathing system contract during inspiration? A external intercostal and diaphragm only B external intercostal and internal intercostal only C external intercostal, internal intercostal and diaphragm D internal intercostal and diaphragm only

Question

Which process requires energy from respiration? A diffusion B osmosis C protein synthesis D transpiration

Question

What is produced by anaerobic respiration in human muscles? carbon dioxide lactic acid water A key B = substance is produced C = substance is not produced D

Question

Which statements are correct for a healthy person? 1 Blood leaving a glomerulus has the same concentration of glucose as blood entering a glomerulus. 2 There is no glucose in the fluid leaving a nephron. 3 A nephron reabsorbs all of the water and some of the ions filtered out of the blood by a glomerulus. A 1 and 3 B 1 only C 2 and 3 D 2 only

Question

When moving from an area with low light intensity to an area with high light intensity, how do the circular and radial muscles of the iris react? circular muscles radial muscles A contract no change B contract relax C relax contract D relax no change

Question

The graph shows the change in the percentage of infections caused by antibiotic-resistant bacteria in one country. 70 60 50 percentage of 40 infections caused by antibiotic-resistant bacteria 30 20 10 0 1981 1986 1991 1996 2001 year Which statements could explain the change in the percentage of infections caused by antibiotic-resistant bacteria? 1 The use of antibiotics has resulted in natural selection for resistant bacteria. 2 The use of antibiotics has caused a decrease in viral diseases. 3 The use of antibiotics when not essential increased the percentage of antibiotic-resistant infections. A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

Question

A gardener has a strawberry plant that produces large, sweet fruits. How does the gardener grow more strawberry plants that all produce large, sweet fruits? A Use asexual reproduction to produce offspring with no genetic variation. B Use asexual reproduction to produce seeds that will grow into new plants. C Use sexual reproduction and self-pollination as they only have one plant. D Use sexual reproduction to reduce variation in the offspring.

Question

Where does fertilisation occur in a plant? A ovule B pollen grain C pollen tube D stigma

Question

The graph shows the concentrations of two hormones during pregnancy. concentration of hormone hormone X oestrogen time Which organ secretes the most hormone X in the late stages of pregnancy? A ovary B placenta C uterus D vagina

Question

A person has a 28-day menstrual cycle. On which day is the lining of the uterus thickest? A 2 B 4 C 9 D 21

Question

Which statements describe the sex chromosomes in human gametes? 1 Egg cells contain either an X or a Y chromosome. 2 Egg cells contain only X chromosomes. 3 Sperm cells contain either an X or a Y chromosome. 4 Sperm cells contain only Y chromosomes. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which statement describes the effect of meiosis on chromosome number? A A diploid parent cell produces diploid daughter cells. B A diploid parent cell produces haploid daughter cells. C A haploid parent cell produces diploid daughter cells. D A haploid parent cell produces haploid daughter cells.

Question

A female with red-green colour blindness has a child with a male who does not have red-green colour blindness. The child is male. What is the chance of this child having red-green colour blindness? A 0% B 25% C 50% D 100%

Question

What is a source of genetic variation that alters the base sequence of DNA? A gene mutation B mitosis C random fertilisation D random mating

Question

Which technique is not used to conserve endangered animal species? A artificial insemination B captive breeding programmes C in vitro fertilisation D seed banks

Question

Which flowchart shows how energy is transferred from the Sun to an organism? chemical energy energy trapped A stored in plants in carbohydrates by chlorophyll chemical energy energy trapped B stored in plants in carbohydrates by chlorophyll energy trapped chemical energy C stored in plants by chlorophyll in carbohydrates energy trapped chemical energy D stored in plants by chlorophyll in carbohydrates

Question

Which statements about a food chain are correct? 1 Between trophic level 1 and trophic level 2, energy is passed from a herbivore to a carnivore. 2 Between trophic level 2 and trophic level 3, energy is passed from a primary consumer to a secondary consumer. 3 Between trophic level 3 and trophic level 4, energy is passed from a secondary consumer to a tertiary consumer. A 1 and 3 B 1 only C 2 and 3 D 2 only

Question

Which process in the nitrogen cycle is involved in the breakdown of amino acids in living organisms? A deamination B decomposition C denitrification D digestion

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The diagram shows part of the carbon cycle. Which arrow represents photosynthesis? carbon dioxide in the atmosphere D B C A animals combustion plants decomposers

Question

The graph shows how the size of a population changes over time. 3 population 4 size 2 1 time Which row identifies the phases of population growth? exponential death phase lag phase phase A 3 1 4 B 3 2 1 C 4 1 3 D 4 2 1

Question

Eutrophication results in a reduction in the dissolved oxygen in streams and lakes. What causes the reduction in dissolved oxygen? A decreased aerobic respiration by decomposers B decreased aerobic respiration by fish C increased aerobic respiration by decomposers D increased aerobic respiration by fish

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What are reasons for using chemical fertilisers in food production? to reduce competition to reduce the to increase between crops use of herbicides crop yields and weeds A yes yes yes B no yes no C yes no no D no no yes

Question

Why is pectinase useful in fruit juice production? A Cloudier juice is produced. B More juice can be extracted from the fruits. C Proteins in the fruit are digested. D Starch is digested to produce more sugar.

Question

The diagrams show the stages in the production of human insulin. Which stage uses the enzyme DNA ligase? A B The gene for insulin is identified A plasmid is removed from and removed from a human cell. a bacterium and cut open. C D The gene for insulin is The plasmid is inserted into a bacterium inserted into the plasmid. that reproduces, and insulin is produced.