Biology 9700/13 October/November 2024: question paper and mark scheme

Question

Which steps are needed to find the actual width of a xylem vessel viewed in transverse section using a ×10 objective lens? 1 Convert from mm to μm by multiplying by 10–3. 2 Calibrate the eyepiece graticule using a stage micrometer on a ×4 objective lens. 3 Measure the width of the xylem vessel using an eyepiece graticule. 4 Multiply the number of eyepiece graticule units by the calibration of the eyepiece graticule. A 1, 2, 3 and 4 B 1 and 2 only C 2, 3 and 4 only D 3 and 4 only

Question

Which cell structure is found in human cells and typical plant cells? A 70S ribosomes B cilia C plasmodesmata D tonoplast

Question

Which statements are correct for a typical prokaryotic cell? 1 It contains 70S ribosomes. 2 It contains a cellulose cell wall. 3 It contains circular DNA. 4 It is up to 5 μm in diameter. A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Question

The diagram shows a typical animal cell. X What is the function of the membrane system labelled X? A lipid synthesis only B protein synthesis and transport C protein synthesis only D protein transport only

Question

What describes a lysosome? A a vesicle containing enzymes, enclosed by a double membrane, that is budded off the endoplasmic reticulum B a vesicle containing hydrolytic enzymes and surrounded by a single membrane, found only in phagocytes C a vesicle enclosed by a single membrane, containing several different hydrolytic enzymes that may act inside or outside the cell D a vesicle surrounded by a double membrane, containing enzymes which can hydrolyse damaged organelles in a cell

Question

The diagram shows a triglyceride. O H H H H H H H H H H C C C C C C C C C C H H C O H H H H H H H H H O H H H H H H H H H C C C C C C C C C C H H C O H H H H H H H H H O H H H H H H H H C C C C C C C H C C H C O H H H H H C H H H H What will be the products after hydrolysis of this triglyceride? A 1 molecule of glycogen, 3 unsaturated fatty acids and 3 molecules of water B 1 molecule of glycerol, 2 saturated fatty acids and 1 unsaturated fatty acid C 1 molecule of glycogen, 2 saturated fatty acids and 1 unsaturated fatty acid D 1 molecule of glycerol, 1 saturated fatty acid, 2 unsaturated fatty acids and 3 molecules of water

Question

Which description lists all the components of a human haemoglobin molecule? A four polypeptides that are all the same and one haem group B four polypeptides that are not all the same and one haem group C four polypeptides that are all the same and four haem groups D four polypeptides that are not all the same and four haem groups

Question

HIV-1 protease is an enzyme produced by the HIV virus. Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 25, 26 and 27 in the sequence form part of the active site. Which orders of protein structure control the shape of the active site? A primary, secondary, tertiary and quaternary B primary, secondary and tertiary only C primary and quaternary only D quaternary only

Question

Which statements are correct reasons for how animals cool down in hot environments using latent heat of vaporisation of water? 1 Some animals lie down and roll in wet soil. 2 Fish move into deeper water. 3 Some animals lick their fur to make it wet. 4 Some animals breathe quickly with a wet tongue hanging out of their mouth. A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Question

Two different enzymes, P and Q, are investigated to find the optimum pH for each enzyme. The results show that P works only in acidic conditions. Q has an optimum pH which is slightly alkaline. Which graph shows the correct results for P and Q? A B Q P Q substrate rate of P concentration reaction at 1 minute 0 7 14 0 7 14 pH pH C D 14 7 Q pH 7 P pH P Q 0 0 product concentration rate of reaction at 1 minute

Question

A student investigated the effect of substrate concentration on the rate of an enzyme-catalysed reaction. The student plotted the results in a graph. 40 30 reaction rate 20 / mol dm–3 s–1 10 0 0 10 20 30 40 50 substrate concentration / mol dm–3 What is the Km for this enzyme-catalysed reaction? A 12 mol dm–3 B 15 mol dm–3 s–1 C 30 mol dm–3 s–1 D 50 mol dm–3

Question

Which statements could be used to describe enzyme molecules and antibody molecules? 1 Hydrogen bonds stabilise the structure of the protein and are important for it to function efficiently. 2 Hydrophilic R-groups point in to the centre of the molecule and cause it to curl into a spherical shape. 3 The tertiary structure of the protein molecule plays an important role in the functioning of the protein. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Which description identifies a reversible, non-competitive enzyme inhibitor? A It can attach to the active site. B It can attach to a site other than the active site. C It can attach to the active site and another site simultaneously. D It can attach to either the active site or another site.

Question

Before mitochondria are extracted from cells for microscopy, they are usually kept in a 0.25 mol dm–3 sucrose solution. Why is the sucrose solution used? A to act as a solvent B to enable the rate of reaction of the mitochondria to be determined C to prevent the mitochondria from changing in dimension D to provide a source of energy

Question

The photomicrograph shows a type of blood cell. Which statements about these cells are correct? 1 Oxygen diffuses through the phospholipid bilayer. 2 Sodium ions diffuse through the phospholipid bilayer. 3 Water passes in and out of these cells by osmosis. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Which row is correct for parts of a phospholipid molecule? can be saturated can also be found or unsaturated in a triglyceride A head tail B tail head C head head D tail tail

Question

A student filled dialysis tubing with a sucrose solution and knotted both ends. This formed a cylinder with a length of 5.0 cm and a radius of 2.0 cm. What is the surface area to volume ratio for this cylinder of dialysis tubing? A 0.7 : 1.0 B 1.0 : 1.0 C 1.4 : 1.0 D 2.5 : 1.0

Question

Which process does not involve mitosis? A asexual reproduction B growth of unicellular organisms C repair of tissues by cell replacement D replacement of damaged or dead cells

Question

The photomicrograph shows cells in an onion root tip. X Y Z Which labelled cells are in anaphase, metaphase and prophase? anaphase metaphase prophase A X Y Z B Y Z X C Z X Y D Z Y X

Question

The diagram shows an outline of the mitotic cell cycle. 1 2 cytokinesis 3 Which numbered stages of the cell cycle include a period of time when each chromosome consists of sister chromatids joined by a centromere? A 1 and 2 B 1 and 3 C 2 and 3 D 2 only

Question

The diagram shows part of a nucleic acid molecule. A X G U C What is the name of bond X? A glycosidic bond B hydrogen bond C peptide bond D phosphodiester bond

Question

XNA is a laboratory-made nucleic acid. XNA is made of nucleotides in which one component has been replaced by chemical X. The chemical X is organic but is not found in nature. The part of the molecule responsible for coding is not changed. Which component of a DNA or RNA nucleotide has been replaced by the organic chemical X? A five-carbon sugar B phosphate group C purine base D pyrimidine base

Question

Which strand of DNA does RNA polymerase bind to? A lagging strand B leading strand C non-transcribed strand D template strand

Question

Which processes occur during the formation of messenger RNA? 1 condensation 2 polymerisation 3 replication 4 transcription A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Question

The anticodon for the amino acid tryptophan is ACC. What shows a template DNA sequence that includes the DNA triplet for tryptophan? A UGG CGU CCG B GCU GAC ACG C CTT TGG ATG D CCT ACC CAT

Question

A student drew a plan diagram of some plant tissue. The diagram is shown. It contains a mistake in the way that it is drawn. R The maximum width of R is 15 mm on the diagram and its actual width is 250 μm. The student was asked to draw a scale bar on their diagram. Which row is correct? length of scale bar part of the location of in mm to correctly plant drawn drawing mistake represent 100 μm A root phloem 6 B root xylem 170 C stem phloem 170 D stem xylem 6

Question

Four students have drawn and labelled part of a structure seen on an electron micrograph. Which student has labelled their drawing correctly? A B vacuole mitochondria mitochondria sieve plate sieve plate thin cytoplasm C D nucleus chloroplast sieve plate sieve plate thin cytoplasm thin cytoplasm

Question

The diagram shows some structures used for transport in the phloem. cell Y companion cell Z cell direction of phloem sieve tube transport long distance Which statement is correct? A Cell Y is the sink cell. B Cell Z can be above or below cell Y in the plant. C Cell Z must be in a photosynthetic tissue. D Cell Y allows glucose to move to the sieve tube via the companion cell.

Question

The diagram shows a section through a root of a dicotyledonous plant. soil particle root hair root cell xylem cell vessel Casparian strip Which statement correctly describes the movement of water and solutes through this root? A A layer of suberin causes water and solutes to move from the apoplast pathway into the symplast pathway. B A layer of suberin causes water and solutes to move from the symplast pathway into the apoplast pathway. C The tonoplast causes water and solutes to move from the symplast pathway into the apoplast pathway. D The tonoplast causes water and solutes to move from the apoplast pathway into the symplast pathway.

Question

The graph shows the effect of different partial pressures of carbon dioxide (CO2) on the oxygen dissociation curve for haemoglobin. 100 80 partial pressure CO2 1.0 kPa 60 percentage partial pressure CO2 saturation of 1.5 kPa haemoglobin with oxygen 40 20 0 0 1 2 3 4 5 6 7 8 9 10 11 12 partial pressure of oxygen / kPa What is the change in percentage oxygen saturation of haemoglobin at a partial pressure of oxygen of 6 kPa as the partial pressure of carbon dioxide changes from 1.0 kPa to 1.5 kPa? A –26% B –20% C 20% D 46%

Question

What happens in the heart at the start of ventricular diastole? A The semilunar valves open. B The atrioventricular valves open. C The pressure in the atria rises above the pressure in the ventricles. D The pressure in the left atrium rises more than the pressure in the right atrium.

Question

The electron micrograph shows a longitudinal section through a blood vessel. blood vessel Which type of blood vessel is shown? A arteriole B capillary C vein D venule

Question

A student drew a sketch to show the formation of tissue fluid. Which label is correct? A D blood enters higher volume capillary and capillary of blood pressure increases returns to vein tissues B C red blood cells higher water potential in and water move tissue fluid so water moves into tissues back into the capillary

Question

Which structures are present in the trachea and also in all bronchioles? 1 cartilage 2 smooth muscle 3 epithelial cells A 1, 2 and 3 B 1 only C 2 and 3 only D 2 only

Question

The photomicrograph shows a section through part of the gas exchange system. Which tissue can be seen? A cartilage B ciliated epithelium C smooth muscle D squamous epithelium

Question

What is the function of the goblet cells in the gas exchange system? A to increase the surface area B to move mucus C to release mucus D to trap dust and pathogens

Question

Which organisms have cell walls that can be affected by penicillin? 1 bacteria 2 protoctists 3 viruses A 1 and 2 B 1 and 3 C 1 only D 2 and 3

Question

Each year, there are 462 000 deaths from malaria in children under 5 years old globally. Insecticide-treated nets could prevent 50% of malaria cases and reduce deaths of children under 5 years old by 18%. How many children could be saved by using insecticide-treated nets? A 41 580 B 83 160 C 231 000 D 332 640

Question

Which row is correct? involved in secrete phagocytosis antibodies A T-lymphocytes B-lymphocytes B T-lymphocytes T-lymphocytes C B-lymphocytes B-lymphocytes D B-lymphocytes T-lymphocytes

Question

Four steps that occur during the primary immune response to a pathogen are listed. P B-lymphocytes divide by mitosis. Q T-helper cells interact with macrophages that have digested pathogens. R Plasma cells secrete antibodies. S T-helper cells activate other lymphocytes. These steps can be arranged in the sequence in which they occur. Which step occurs third in the sequence? A P B Q C R D S