Biology 0610/23 October/November 2025: question paper and mark scheme

Question

What is a characteristic of all living organisms? A breathing B photosynthesis C reproduction D transpiration

Question

What are the two parts of the scientific name of an organism? A genus followed by kingdom B genus followed by species C kingdom followed by genus D kingdom followed by species

Question

A palisade cell and a neurone are observed under a light microscope. Which cell component is found only in the palisade cell? A cell membrane B cell wall C cytoplasm D nucleus

Question

In a human, the diameter of the aorta as it leaves the heart is 36 mm. The thickness of the wall of the aorta at this point is 9 mm. What is the diameter of the lumen of the aorta at this point? A 1800 m B 2700 µm C 18 000 µm D 27 000 µm

Question

Diffusion may be defined as the net movement of particles from a region of their ……1…… concentration, to a region of their ……2…… concentration, where movement is ……3…… a concentration gradient. Which words complete gaps 1, 2 and 3? 1 2 3 A higher lower down B higher lower up C lower higher down D lower higher up

Question

Cylinders of potato tissue were placed in sugar solutions of different concentrations and left overnight. The lengths of the potato cylinders were measured before and after they were placed in the sugar solutions. The graph shows the results of the investigation. 1.2 1.1 ratio of final length 1.0 to initial length 0.9 0.8 0.1 0.2 0.3 0.4 0.5 sugar solution concentration / moles per dm3 In which sugar solution concentrations did the potato cells gain water? A 0.1 moles per dm3 and 0.2 moles per dm3 B 0.1 moles per dm3 only C 0.2 moles per dm3 and 0.3 moles per dm3 D 0.4 moles per dm3 and 0.5 moles per dm3

Question

The diagrams show the same mass of oil arranged in drops of different sizes at the same temperature. In which combination of oil drop size and enzyme will the oil be digested the fastest? A B C D trypsin lipase lipase trypsin

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Which substance contains magnesium ions? A cellulose B chlorophyll C glucose D glycerol

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The diagram shows part of a cross-section of a leaf. Which part is the xylem? A B C D

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The diagram shows an experiment to investigate gas exchange in a leaf. black cover ink drop substance that absorbs carbon dioxide leaf In which direction does the ink drop move and for what reason? direction reason A towards the leaf photosynthesis B towards the leaf respiration C away from the leaf photosynthesis D away from the leaf respiration

Question

What is an example of chemical digestion? A breaking down starch into reducing sugars B churning of food by muscular contractions of the stomach wall C grinding of food by teeth D mixing of food with bile

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The diagram shows a villus. X Which row shows the name and function of the part labelled X? name function A capillary absorption of amino acids and glucose B capillary absorption of fatty acids and glycerol C lacteal absorption of amino acids and glucose D lacteal absorption of fatty acids and glycerol

Question

Which environmental conditions will result in the highest rate of transpiration? high air low air very windy humidity temperature A no no yes B no yes no C yes yes yes D yes no no

Question

Which statements describe sources and sinks? 1 Palisade mesophyll cells only act as sinks. 2 Roots can act as sinks. 3 Sink cells only receive glucose from the phloem. 4 Spongy mesophyll cells can act as sources. A 1, 2, 3 and 4 B 1, 3 and 4 only C 1 and 3 only D 2 and 4 only

Question

What is a feature of veins? A one-cell-thick wall B narrow lumen C thick muscular walls D valves are present

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The diagram shows a section through a human heart. Which structure is an atrioventricular valve in the right side of the heart? A B D C

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What is an example of active immunity? A antibody production after infection B antibody transfer from mother to baby in breast milk C antibody transfer from mother to fetus across the placenta D an injection of antibodies that were produced by another individual

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Which changes cause expiration? external diaphragm intercostal muscles A contract relaxes and moves down B contract relaxes and moves up C relax relaxes and moves down D relax relaxes and moves up

Question

What shows the pathway of urea from where it is produced to where it is excreted? A kidney → renal artery → heart → lungs → heart → renal vein → bladder B kidney → renal vein → heart → lungs → heart → renal artery → bladder C liver → hepatic artery → heart → lungs → heart → renal artery → kidney D liver → hepatic vein → heart → lungs → heart → renal artery → kidney

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Which row shows the state of the ciliary muscles and suspensory ligaments when the eye is focusing on a near object? ciliary suspensory muscles ligaments A contracted slack B contracted tense C relaxed slack D relaxed tense

Question

Events that occur at a synapse are listed. They are not in the correct order. 1 An impulse is stimulated in the next neurone. 2 An impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap. 3 Neurotransmitter molecules bind with receptor proteins on the next neurone. 4 The neurotransmitter molecules diffuse across the gap. What is the actual sequence of events? A 2→4→1→3 B 2→4→3→1 C 4→2→1→3 D 4→2→3→1

Question

Which actions can prevent a mammal’s internal body temperature falling too low? A shivering and vasoconstriction B shivering and vasodilation C sweating and vasoconstriction D sweating and vasodilation

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The diagram shows the position of some of the human endocrine glands. X Which hormone is secreted by X? A adrenaline B insulin C oestrogen D testosterone

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Which row shows the correct speed and duration for the type of control? type of control speed of action duration of effect A hormonal fast short B hormonal slow long C nervous fast long D nervous slow short

Question

A student writes four statements about auxin. 1 Auxin becomes more concentrated on the lower side of a horizontal stem. 2 Auxin becomes more concentrated on the side of the shoot that has more light. 3 Auxin is made in the shoot tip. 4 Auxin prevents cell elongation in the shoot. Which statements describe what happens during chemical control of plant growth? A 1, 2 and 4 B 1 and 2 only C 1 and 3 D 2, 3 and 4

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What can antibiotics treat? A all diseases caused by pathogens B cholera C HIV (human immunodeficiency virus) D rickets

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The diagram shows two methods of pollination, V and W. The two flowers are on different plants of the same species. V W A student made three conclusions about these two methods of pollination. 1 Method V will produce genetically identical offspring. 2 Method W will produce genetically different offspring. 3 Method W increases the ability of the species to adapt to its surroundings. Which conclusions are correct? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

The diagram shows the blood supply between a fetus and a placenta. capillary in the placenta placenta key direction of umbilical cord blood flow umbilical vein umbilical artery fetus Which row shows the concentration of substances in the umbilical artery and umbilical vein? umbilical artery umbilical vein A high nutrient concentration high urea concentration B high urea concentration high carbon dioxide concentration C low carbon dioxide concentration low nutrient concentration D low oxygen concentration low urea concentration

Question

Which hormone is produced by cells in the placenta of a developing fetus? A FSH B LH C testosterone D progesterone

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What are alleles? A a pair of chromosomes B different versions of the same gene C the total number of genes on one chromosome D two genes side by side on the same chromosome

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Polydactyly in cats is a dominant condition that causes affected cats to be born with extra toes. What is the probability of two cats that are heterozygous for polydactyly having an offspring with no extra toes? A 0.125 B 0.25 C 0.50 D 0.75

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Which statement describes red-green colour blindness? A It is an example of codominance. B It is more common in females than in males. C It only occurs in males. D The recessive allele is located on an X chromosome.

Question

Four features of cell division are listed. 1 Haploid cells are produced. 2 New cells are genetically identical. 3 It is a reduction division. 4 It results in variation. Which features would be associated with meiosis? A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

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Which term is used to describe a characteristic that helps an organism to survive and reproduce in its environment? A adaptive feature B competition C observable feature D phenotype

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Which process removes carbon dioxide from the atmosphere? A combustion B decomposition C photosynthesis D respiration

Question

The diagram shows part of the nitrogen cycle. nitrogen in the atmosphere process Y amino acids proteins in plant and in plants animals and animal waste and animals plants ammonia process X nitrate ions in soil What are the names of process X and process Y? X Y A deamination denitrification B nitrogen fixation deamination C nitrogen fixation nitrification D nitrification denitrification

Question

The graph shows how the population of the world increased from 1650 until the present day. 8 7 6 world 5 population 4 / billions 3 2 1 0 1650 1700 1750 1800 1850 1900 1950 2000 year Which phases of a sigmoid curve of population growth are not shown on this graph? A death and lag B exponential (log) and stationary C lag and exponential (log) D stationary and death

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In which trophic level are herbivores found? A primary consumers B quaternary consumers C secondary consumers D tertiary consumers

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The graph shows the relative amounts of bacteria and dissolved oxygen at different locations along a river. Fertiliser has entered the river. At which distance along the river did the fertiliser enter the river? dissolved oxygen relative amount bacteria A B C D distance along the river

Question

Human insulin can be produced in large quantities by genetically modified bacteria. Four of the steps in the processes of genetic modification and insulin production are listed. 1 Insulin is removed from the bacterial culture. 2 An enzyme is used to cut out the insulin gene from a human chromosome. 3 The insulin gene is placed into the plasmid of a bacterium. 4 Bacteria with the insulin gene reproduce very rapidly. What is the order of these steps? A 1→2→3→4 B 2→3→4→1 C 3→2→4→1 D 4→1→2→3