Biology 9700/13 May/June 2022: question paper and mark scheme

Question

The diagram shows a section through epithelium found in part of the respiratory system. 80 μm What is the magnification of the diagram? A ×35 B ×350 C ×3500 D ×35 000

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 synthesis of polypeptides 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 functions with the appearance of the cell structure? 1 2 3 A V X Y B V Z Z C X W Z D X Z W

Question

An experiment was carried out to separate the cell structures in an animal cell. The cells were broken open. The extract was filtered and put into a centrifuge tube. This tube was then spun so that the heaviest cell structure sank to the bottom first, forming pellet 1, as shown. liquid above pellet pellet 1 The liquid above pellet 1 was poured into a clean centrifuge tube and spun again at a higher speed to separate the next heaviest cell structure. This cell structure sank to the bottom, forming pellet 2. This procedure was repeated twice to obtain pellet 3 and pellet 4, each containing a single cell structure. What is a function of the cell structure extracted in pellet 1? A digestion of old organelles B production of ATP C production of mRNA D synthesis of protein

Question

ATP molecules are synthesised in mitochondria. Which sugar is found in these ATP molecules? A deoxyribose B fructose C glucose D pentose

Question

Which row shows a comparison that is not correct between a typical prokaryotic cell and a typical eukaryotic plant cell? prokaryotic cell eukaryotic plant cell A DNA not associated DNA associated with histones with histones B no endoplasmic reticulum endoplasmic reticulum present present C peptidoglycan cell walls cellulose cell walls D all ribosomes approximately all ribosomes approximately 18 nm in diameter 22 nm in diameter

Question

It is suggested that primitive prokaryotic cells may be ancestors of certain organelles in eukaryotic cells. Which organelle is most similar in composition to a typical prokaryote? A Golgi bodies B lysosomes C mitochondria D nucleoli

Question

The concentration of reducing sugar in a solution can be found if an observational measurement is compared to a standard. Which observational measurement could be used to estimate the concentration of reducing sugar in an unknown solution? 1 the colour of the solution after 20 minutes 2 the time for the first colour change to occur 3 the rate of formation of solid particles A 1, 2 and 3 B 1 and 2 only C 2 only D 3 only

Question

The diagram shows three hexose sugars. CH2OH CH2OH CH2OH O C O C O H H H OH OH H H C C C C C C OH H OH H H OH HO OH HO H H CH2OH C C C C C C H OH H OH OH H 1 2 3 Which row correctly shows examples of carbohydrates in which these three hexose sugars occur? sucrose cellulose amylopectin A 1 2 3 B 1 3 2 C 2 3 1 D 3 2 1

Question

Trehalose is a sugar that gives a negative result when tested with Benedict’s solution. A molecule of trehalose forms two α-glucose molecules when it is hydrolysed. Which row is correct? sugar that gives formula of the same result with trehalose Benedict’s as trehalose A C12H22O11 fructose B C12H22O11 sucrose C C12H24O12 fructose D C12H24O12 sucrose

Question

Olestra is an artificial lipid. It is made by attaching fatty acids, by condensation, to a sucrose molecule. A simplified diagram of olestra is shown. R represents the position where fatty acids would be attached. CH2OR O H H ROCH2 O H H OR H O H RO RO CH2OR H OR OR H Humans cannot hydrolyse olestra. However, other animals may be able to do so. How many molecules of water would be needed to hydrolyse one molecule of olestra into fatty acids, fructose and glucose? A 11 B 10 C 9 D 8

Question

Which molecule contains at least one peptide bond? A B H H O OH HO CH2 C C H C O C R O H O O N HO C CH2 C C H H C O C R H O O N CH3 C C H H C O C R O N H H H C D HOCH2 NH2 CH2OH OH OH C N H O H C N H H H H HC H2 C CH OH H O C N N HO O CH2OH O O H OH – O HC CH P CH CH O O OH

Question

RNA polymerase and peptidyl transferase are both enzymes involved in protein synthesis. Which statements describe similarities between these two enzymes? 1 They are both globular proteins. 2 They both have the same tertiary structure. 3 They are both intracellular enzymes. A 1 and 2 B 1 and 3 C 1 only D 2 and 3

Question

What is a feature of competitive enzyme inhibition? A The inhibitor binds permanently to the active site. B Inhibition can be reversed by increasing the concentration of the substrate. C The inhibitor molecule changes the secondary structure of the enzyme. D The substrate and the inhibitor are the same shape.

Question

Batrachotoxin is a poison found in frogs in the Colombian jungle. The poison is used to produce poison darts. The poison works by increasing the permeability of the cell surface membrane of nerve and muscle cells to sodium ions, which move out of the cells. Four students made statements about how the poison affects the cells. 1 Water leaves the cells by osmosis, causing the cells to shrink. 2 Water enters the cells by osmosis, causing the cells to burst. 3 When the sodium ions move out of the cells the intracellular fluid has a more positive water potential than the extracellular fluid. 4 When the sodium ions move out of the cells the extracellular fluid has a more positive water potential than the intracellular fluid. Which statements are correct for the cells affected by batrachotoxin? A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which processes use energy in the form of ATP? 1 endocytosis 2 exocytosis 3 facilitated diffusion A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

An indicator is colourless in acid and pink in alkali. In an experiment a petri dish of agar was prepared using an acidic solution of this indicator. A disc of agar 1 cm in diameter was removed from the centre to create a well. A white card showing circular marker lines 1 cm apart was placed underneath the petri dish. 1 cm3 alkali solution was put into the well in the agar and a stop-watch was started. A circular disc of pink colour appeared and spread through the agar. It reached the first marker line in a short time but took longer to reach the second marker line and a very long time to reach the third marker line. What explains these observations? A facilitated diffusion of alkali solution B facilitated diffusion of the indicator C simple diffusion of alkali solution D simple diffusion of the indicator

Question

The diagram shows a section of a glycoprotein molecule found embedded in a cell surface membrane. Each of the amino acids is represented by a small shaded circle. amino acid Q amino acid chain forms an alpha helix Which row shows a property of the amino acids found in the alpha helix and a property of amino acid Q? property of property of amino acids found amino acid Q in the alpha helix A non-polar polar B non-polar non-polar C polar polar D polar non-polar

Question

Some cells are listed. 1 bacterial cells 2 cancer cells 3 lymphocytes 4 mature red blood cells 5 stem cells Which cells can divide by mitosis? A 1, 2, 4 and 5 B 1, 2 and 3 C 2, 3 and 5 D 3, 4 and 5

Question

Which statements about mitosis are correct? 1 At the end of telophase, two nuclei are formed. 2 Centrioles attach chromosomes to the spindle during metaphase. 3 Chromatids are pulled apart during anaphase. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Which statement about telomeres is correct? A They allow cells in culture from any age of donor to divide a fixed number of times. B They are genes which are present on the 5′ end of every chromosome. C They are unpaired regions of DNA on the 3′ end of every chromosome. D They prevent introns and exons being lost from genes during cell division.

Question

The diagram shows stages of mitosis. 1 3 2 5 4 What is the correct sequence of the stages of mitosis numbered on the diagram? A 1→3→4→2→5 B 1→3→4→5→2 C 3→1→4→5→2 D 3→4→1→2→5

Question

Which statement about the transcription and translation of a gene is correct? A The non-transcribed strand of DNA has a base sequence that is identical to the mRNA produced in transcription. B The template strand of DNA has a base sequence that is identical to the mRNA produced in transcription. C The non-transcribed strand of DNA has a base sequence that is complementary to the tRNA molecules required in translation. D The template strand of DNA has a base sequence that is complementary to the tRNA molecules required in translation.

Question

Which statement about mRNA is correct? A The primary transcript becomes modified by the joining of introns to become mRNA. B The primary transcript is synthesised and then modified to mRNA in the nucleus. C mRNA contains nucleotides containing the sugar deoxyribose. D The bases in mRNA are held together by covalent bonds.

Question

The diagram shows part of a DNA molecule. O H 3C O O D N O H O N O H N H O O P O– N O O N C O– P O N N N O O N O O O H H A N N N O P O– O H N N O O – P O B H H O N O O O O O P O– O O O– P O O Which label is correct? A adenine B guanine C cytosine D thymine

Question

The sequence of bases in DNA coding for the first eight amino acids in the β-polypeptide of adult haemoglobin is: CAC GTG GAC TGA GGA CTC CTC TTC However, in haemoglobin C, which is a cause of haemolytic anaemia, it becomes: CAC GTG GAC TGA GGA TTC CTC TTC Some of the DNA triplets that code for the amino acids are listed in the table. amino acid DNA triplet Glu CTC His GTG Leu GAG Lys TTC Pro GGA Thr TGA Which change occurs to the amino acid sequence of normal haemoglobin to make it haemoglobin C? A Glutamic acid is changed to lysine. B Histidine is changed to leucine. C Leucine is changed to lysine. D Proline is changed to threonine.

Question

The diagram shows a plant organ. Which letter correctly labels the xylem? B A C D

Question

The photomicrograph shows a vascular bundle found in a plant organ. X Y Which statements about this vascular bundle are correct? 1 The vascular bundle is part of the structure of a root. 2 Some of the cells in region X have very large numbers of mitochondria. 3 Region Y is made up of a number of different cell types. A 1 and 2 B 1 only C 2 and 3 D 3 only

Question

Which changes to the water potential and the volume of solution in the phloem sieve tube element occur when sucrose is moved from the phloem sieve tube element to an actively dividing shoot tip? water potential in volume of solution phloem sieve tube in phloem sieve element becomes tube element A higher decreases B higher increases C lower decreases D lower increases

Question

Which processes occur during the loading of sucrose into phloem sieve tubes? 1 Protons are pumped out of the cytoplasm of the companion cell into its cell wall. 2 There is a higher concentration of protons in the symplastic pathway outside the companion cell. 3 Protons are unable to move back into the companion cell. 4 A co-transporter molecule acts as a carrier for protons and sucrose. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

The photomicrograph shows a section through a structure found in mammals viewed using a light microscope. W ×60 What are the main components of layer W? A collagen fibres only B elastic fibres and collagen fibres C smooth muscle and elastic fibres D squamous epithelial cells forming an endothelium

Question

Which statement correctly links muscular or elastic arteries to their function? A The aorta is an example of a muscular artery as it transports blood from the left ventricle of the heart. B Arteries further away from the heart are muscular arteries as they transport blood at high pressure. C Elastic arteries expand when the heart contracts and then recoil as the heart relaxes to maintain pressure. D Muscular arteries facilitate smoother blood flow than elastic arteries as their walls expand and recoil.

Question

The graph shows the changes in pressure that occur in the left side of the heart during one cardiac cycle. key pressure left ventricle aorta left atrium 0 0.2 0.4 0.6 0.8 time / s What is the heart rate in beats per minute? A 75 B 80 C 120 D 150

Question

Which events occur during ventricular systole? 1 Atrioventricular valves close. 2 Muscle in ventricle walls relaxes. 3 Semilunar valves open. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Which reactions take place in a capillary in the lungs? 1 Carbonic acid is formed from carbon dioxide and water. 2 Carbaminohaemoglobin is formed from carbon dioxide and haemoglobin. 3 Haemoglobinic acid is formed from haemoglobin and hydrogen ions. 4 Carbon dioxide and water are formed from hydrogencarbonate ions and hydrogen ions. A 1 and 2 B 3 and 4 C 3 only D 4 only

Question

Which features are important for the process of diffusion of oxygen out of an alveolus? 1 blood pressure forces red blood cells through capillaries 2 4 epithelium is substance to reduce features permeable to surface tension respiratory gases 3 moist squamous epithelium present A 1, 2 and 3 B 1, 3 and 4 C 1 and 3 only D 2 and 4

Question

A student viewed three slides at both low magnification and high magnification. Each slide was a section through a different airway of the gas exchange system. The student observed three features in each slide. slide three features observed by student 1 irregular arrangement of cartilage highly folded inner layer cilia on epithelial cells 2 very few goblet cells cilia on epithelial cells thick layer of smooth muscle relative to wall thickness 3 smooth muscle tissue blood vessels many goblet cells Which row correctly identifies the three slides? slide 1 slide 2 slide 3 A bronchus bronchiole trachea B bronchus trachea bronchiole C trachea bronchiole bronchus D trachea bronchus bronchiole

Question

Which terms can be used to describe the role of mosquitoes in the transmission of malaria? 1 malarial parasite 2 pathogen 3 vector A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 3 only

Question

Rheumatoid arthritis is a disease which causes the body’s immune system to attack its own cells. The disease can be treated using monoclonal antibodies. The table shows how five different monoclonal antibodies can work. monoclonal mode of action antibody 1 binding to proteins on cell surfaces and triggering the immune system 2 blocking molecules on cell surfaces that inhibit T-lymphocytes 3 blocking cell signalling receptors that trigger cell division 4 binding to antigens on cell surfaces and releasing a drug 5 blocking cell signalling receptors that trigger the immune response Inflammation and swelling of joints are symptoms of rheumatoid arthritis. The cytokine, TNFalpha, activates cells in the immune system leading to death of cells in the joint. Which types of monoclonal antibody could be used to treat rheumatoid arthritis? A 1, 2, 3, 4 and 5 B 1, 2, 3 and 4 only C 2, 3 and 5 only D 4 and 5 only

Question

A person’s blood group is determined by antigens present on the red blood cells. Antibodies in the plasma of the person who receives the blood can make some blood transfusions unsafe. 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 Which blood groups can be given to a person with blood group A? A A and AB B A and O C B and O D AB only

Question

Some of the events during the primary immune response are listed. 1 phagocytosis of a foreign microbe by a macrophage and antigen presentation 2 some T-lymphocytes will become T-killer cells which kill infected body cells 3 the T-helper cell divides by mitosis to produce T-lymphocyte clones 4 a T-helper cell with the complementary receptor binds to the antigens being presented What is the correct sequence of events during the primary immune response? A 4→1→3→2 B 1→4→3→2 C 3→1→4→2 D 3→4→1→2