Biology 9700/11 May/June 2022: question paper and mark scheme

Question

A student used a stage micrometer scale to calibrate an eyepiece graticule. The diagram shows the view of both the stage micrometer scale and the eyepiece graticule seen by the student. The divisions on the stage micrometer scale are 0.1 mm apart. stage micrometer scale eyepiece graticule 0 10 20 30 40 50 60 70 80 90 10 The student removed the stage micrometer scale and viewed a slide with blood cells on it. The same lenses were used so that the magnification remained unchanged. The student measured the diameter of one of the white blood cells on the slide using the eyepiece graticule and recorded that it was 8 eyepiece units. What is the correct diameter of this white blood cell in micrometers? A 0.2 B 0.8 C 20 D 800

Question

Four students were asked to match the function with the appearance of some cell structures in an animal cell. The functions were listed by number. 1 mRNA passes through to the ribosome 2 produces the mitotic spindle during cell division 3 packaging of hydrolytic enzymes that will remain in the cell The appearances were listed by letter. V membranes which surround an enclosed inner cavity W non-membrane-bound, spherical structures X a double membrane interspersed with pores Y non-membrane-bound, cylindrical structures Z membrane-bound sacs, arranged as a flattened stack Which student correctly matched the numbered function with the appearance of the cell structure? 1 2 3 A V W Y B V Y Z C X W Y D X Y Z

Question

Which size range would include most prokaryotic cells? A B C D 1 nm 100 nm 1 µm 100 µm 1 mm

Question

What is present in a typical prokaryotic cell and a typical eukaryotic cell? A 70S ribosomes B centrioles C circular DNA in the cytoplasm D starch granules

Question

Which statement about viruses is correct? A They all have a capsid made of protein. B They all contain RNA. C They all have an outer envelope made of phospholipids. D They all contain 80S ribosomes.

Question

Samples of glucose, sucrose, and a mixture of glucose and sucrose were divided into two halves M and N. M was then tested with Benedict’s solution. N was boiled with dilute hydrochloric acid, neutralised and then tested with Benedict’s solution. The colour of the solution was compared to colour standards. Which table identifies the correct colour changes for these samples? A B sample M N sample M N glucose blue blue glucose yellow yellow sucrose blue yellow sucrose blue yellow mixture blue yellow mixture blue yellow C D sample M N sample M N glucose yellow yellow glucose yellow red sucrose blue yellow sucrose blue red mixture yellow red mixture yellow red

Question

Which molecules contain 1,4-glycosidic bonds? amylose A D B C cellulose glycogen

Question

The diagram shows three triglycerides, X, Y and Z. O H2COC O X HCOC O H2COC O H2COC O Y HCOC O H2COC O H2COC O Z HCOC O H2COC Which row is correct for these triglycerides? contains contains contains more saturated unsaturated than two different fatty acids fatty acids fatty acids A X, Y and Z X and Y X and Y B X, Y and Z Z X and Y C X and Y X, Y and Z X, Y and Z D Z X and Y X, Y and Z

Question

Some foods contain hydrogenated vegetable fats. These are unsaturated fats that have been converted to saturated fats. Which property of the fats will have changed? A Their hydrocarbon chains will fit together more closely. B Their solubility in water will increase. C They will have more double bonds in their molecules. D They will remain liquid at room temperature.

Question

A polypeptide contains a specific number of amino acids, n. How many peptide bonds are present in this polypeptide? A n–1 B n C n+1 D n+2

Question

Which statement is correct? A Amylase, ribose and phospholipid are all macromolecules. B Cellulose, glucose and catalase are all polymers. C Deoxyribose, fructose and ribose are all monosaccharides. D Sucrose, deoxyribose and amylopectin are all polysaccharides.

Question

A student used colorimetry to monitor the hydrolysis of a protein by a protease enzyme. The student used biuret solution to determine the concentration of protein in the hydrolysis reaction. The student produced a calibration curve using known concentrations of protein. Which diagram shows the calibration curve? A B transmission absorbance 0 0 0 protein 0 protein concentration concentration C D transmission absorbance 0 0 0 protein 0 protein concentration concentration

Question

A student completed an experiment to measure how increasing concentrations of substrate affects the rate of an enzyme-controlled reaction. The student then repeated the experiment after adding a fixed quantity of a reversible competitive inhibitor. Which row describes the effect of a reversible competitive inhibitor on enzyme activity? attachment of inhibitor effect of increasing substrate concentration at active site on rate of enzyme-controlled reaction A no little effect on the rate B yes rate increases C no rate increases D yes little effect on the rate

Question

The diagram shows a liposome. 1 2 Liposomes can be used to move therapeutic drugs into cells of the body to treat conditions such as cancer. Which row shows the property of a drug that could be transported in the sections of the liposome labelled 1 and 2? property of drug property of drug transported in location 1 transported in location 2 A hydrophilic hydrophilic B hydrophilic hydrophobic C hydrophobic hydrophilic D hydrophobic hydrophobic

Question

Some processes occurring in cells are listed. 1 endocytosis of water into cells 2 exocytosis of enzymes from cells 3 facilitated diffusion of glucose into red blood cells 4 phagocytosis of dead cells by macrophages Which processes use ATP? A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Question

The graph shows changes in the concentration of a solute inside a cell. concentration of solute inside cell 0 0 time What explains this change in concentration? 1 diffusion 2 endocytosis 3 exocytosis 4 osmosis A 1, 2 and 3 B 1, 3 and 4 C 1 and 4 only D 2 and 4

Question

The indicator cresol red, changes from red to yellow when put into acid. Four blocks of agar containing cresol red were cut to different sizes measured in millimetres. The blocks were submerged in acid. All other variables were kept constant. The time taken for each of the blocks to completely turn yellow was recorded. Which of the four blocks became completely yellow most quickly? A 3 × 30 × 30 B 6×6×6 C 6 × 12 × 12 D 12 × 12 × 12

Question

Which processes require mitosis? 1 the cloning of T-lymphocytes 2 the repair of cell structures by protein synthesis 3 the growth of multicellular organisms from a single cell 4 the reproduction of a unicellular eukaryote A 1, 2 and 3 B 1, 3 and 4 C 1 and 2 only D 3 and 4 only

Question

Which events listed are part of the cell cycle? 1 interphase 2 prophase 3 cytokinesis A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Telomerase is an enzyme that adds nucleotides to telomeres. Which statement about telomerase is correct? A A high concentration of telomerase in a cell damages genes during DNA replication. B A high concentration of telomerase in cancerous cells limits the rate of tumour growth. C The low concentration of telomerase in stem cells means that these cells can divide an unlimited number of times. D The low concentration of telomerase in body cells means that these cells can divide a limited number of times.

Question

The photomicrograph shows cells at different stages of mitosis. P T Q S R A student wrote four statements about the photomicrograph. 1 Cell P shows anaphase. 2 Spindle formation is occurring in cell Q. 3 The amount of DNA in cell R is the same as in cell T. 4 The correct order for the stages is S → R → T → P → Q. Which statements are correct? A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Question

Bacterial cells with DNA containing only the ‘heavy’ isotope of nitrogen (15N) are allowed to reproduce for three generations in a culture medium containing the normal isotope of nitrogen (14N). Which percentage of the DNA molecules produced contain strands with the heavy isotope of nitrogen? first generation second generation third generation % % % A 50 25 12.5 B 75 50 25 C 100 50 25 D 100 75 50

Question

A bacterial circular DNA molecule is 2 600 150 base pairs long. 26% of the bases are adenine. How many cytosine bases would be in the DNA molecule? A 624 036 B 676 039 C 1 248 072 D 1 352 078

Question

Which statement relating to the structure of DNA is correct? A Two DNA strands are joined to each other by phosphodiester bonds. B The alignment of bases to form a double helix is only achieved between antiparallel strands. C Three hydrogen bonds are formed between all base pairs containing purines. D The number of cytosine bases always equals the number of thymine bases.

Question

A student sketched a diagram to represent the process of transcription. Which part of their diagram shows the non-transcribed strand? T A A T A G C B C G T UA T UA C CG direction of D A AT transcription C CG G GC G GC T A T A C A T CG

Question

Which row is correct for the movement of water in a root? molecule present pathway in Casparian strip A apoplast pathway through intercellular spaces suberin B apoplast pathway through plasmodesmata lignin C symplast pathway through plasmodesmata lignin D symplast pathway through intercellular spaces suberin

Question

The table contains some information about uptake and movement of water and of mineral ions in plants. water mineral ions mechanism for uptake osmosis diffusion, active transport site of uptake root hair cells root hair cells mechanism of release evaporation, diffusion diffusion, active transport site of release stomata plant cells Using the information provided, which factors will affect the uptake and movement of water or of mineral ions in plants? 1 humidity 2 surface area of root hair cell 3 oxygen concentration 4 temperature A 1, 2, 3 and 4 B 1, 3 and 4 only C 1 and 3 only D 4 only

Question

Which changes to the water potential and the volume of solution in the phloem sieve tube occur when sucrose is moved from a photosynthesising leaf into the phloem sieve tube? water potential in volume of solution the phloem sieve in the phloem tube becomes sieve tube A higher decreases B higher increases C lower decreases D lower increases

Question

A student wrote the following statements about a possible mechanism for loading sucrose from a source. 1 When energy is released from ATP, the released energy is used to move sucrose through a co-transporter protein in the companion cell membrane. 2 As sucrose is moved into a companion cell the pH in the cell wall of the companion cell decreases. 3 Proton pumps in the cell membrane of a companion cell move sucrose into the phloem sieve tube element. Which statements are correct? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only

Question

The diagram shows a transverse section through an artery. X Which tissues are present in layer X? A collagen and smooth muscle only B elastic fibres and collagen only C elastic fibres and smooth muscle only D elastic fibres, collagen and smooth muscle

Question

What is systolic blood pressure? A the blood pressure in the arteries when the heart is relaxing B the blood pressure in the left ventricle at the start of a contraction C the maximum blood pressure in the arteries D the maximum blood pressure in the right ventricle

Question

The diagram shows pressure changes in the left side of the heart and aorta over time. The length of this cardiac cycle is 0.6 s. Points 1, 2, 3 and 4 indicate when atrioventricular valves and semilunar valves either open or close. 18 16 3 14 2 12 10 pressure / kPa key 8 left ventricle 6 aorta 4 4 left 1 atrium 2 0 0 0.1 0.2 0.3 0.4 0.5 0.6 time / s What is the total time during one cardiac cycle that the atrioventricular valves and the semilunar valves are both closed at the same time? A 0.03 s B 0.04 s C 0.07 s D 0.21 s

Question

Which reactions take place in the capillaries surrounding an alveolus? 1 carbon dioxide + water → carbonic acid 2 carbon dioxide + haemoglobin → carbaminohaemoglobin 3 haemoglobinic acid → haemoglobin + hydrogen ions 4 hydrogencarbonate ions + hydrogen ions → carbonic acid → carbon dioxide + water A 1 and 2 B 3 and 4 C 3 only D 4 only

Question

Which statement explains the importance of the chloride shift in red blood cells (RBC)? A Carbon dioxide diffuses from blood plasma into RBC and chloride ions diffuse out of RBC to maintain a balance of positive and negative ions. B Hydrogencarbonate ions diffuse into plasma from RBC and chloride ions diffuse into RBC to maintain a balance of positive and negative ions. C Carbon dioxide in RBC together with chloride ions stimulate the release of oxygen from haemoglobin to allow increased levels of respiration. D Hydrogencarbonate ions diffuse into RBC from plasma and chloride ions diffuse into plasma to maintain a balance of positive and negative ions.

Question

The photomicrographs show a cross-section through the lining of part of the respiratory system. Which statements about the photomicrographs are correct? 1 Goblet cells are visible between squamous epithelium cells. 2 Smooth muscle is visible. 3 The section cannot be from a bronchiole as cartilage is visible. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

The surface tension of the layer of liquid lining the alveoli tends to pull the walls inwards so alveoli could collapse. Which statements could explain how this is prevented? 1 Alveolar fluid is moved around by cilia. 2 Elastic fibres keep the alveoli open. 3 Epithelial cells secrete a chemical that reduces the cohesion in water. A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

Question

What will reduce the rate at which bacteria become resistant to antibiotics? 1 prescribing two antibiotics with different modes of action 2 prescribing different antibiotics for the same bacterium 3 finishing a prescribed course of antibiotics A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

T-lymphocytes have a protein, PD-1, on their surface. Some cancer cells have a receptor molecule on their surface which binds with PD-1, inactivating the T-lymphocyte. A monoclonal antibody, lambrolizumab, has been produced against this receptor. Trials showed that in 54 of 135 people with advanced skin cancer who were given lambrolizumab the tumours more than halved in volume. In six of the 57 people who were given the highest dose the tumours disappeared. What may be correctly concluded from this information? 1 Lambrolizumab binds with a receptor on the surface of skin cancer cells. 2 Cancer cells to which lambrolizumab is bound cannot inactivate T-lymphocytes. 3 Lambrolizumab targets and kills skin cancer cells. 4 Lambrolizumab allows a patient’s own immune system to kill cancer cells. A 1, 2, 3 and 4 B 1, 2 and 4 only C 1 and 3 only D 2, 3 and 4 only

Question

A person’s blood group is determined by antigens present on the red blood cells. The table shows the antigens and antibodies in the blood of people with different blood groups. presence of A or B antigens presence of antibodies to blood group on red blood cells A or B in plasma A A only anti-B only B B only anti-A only AB A and B neither O neither anti-A and anti-B During a blood transfusion, it is essential that the person receiving the blood does not have antibodies to the donor’s blood. Which blood groups can be given to a person with blood group AB? A AB only B O only C A and B only D A, B, AB and O

Question

Which types of cell are stimulated to divide by the cytokines produced by T-helper cells? A macrophages B B-lymphocytes only C T-killer cells only D B-lymphocytes and T-killer cells