CAIE Biology (9700)

The diagram shows a plant cell with some labelled structures. Which labelled structures are bound by a double membrane? A P and Q B P and S C R and Q D R and S

Which size of ribosome is found in mitochondria and typical prokaryotic cells? A 50S B 60S C 70S D 80S [Turn over

Which row about typical prokaryotic cells and typical animal cells is correct? lysosomes present for the break down of old organelles ATP is produced by the cell A 3 7 B 3 3 C 7 3 D 7 7 key = correct for typical prokaryotic cells and typical animal cells

= not correct for both cells but correct for either typical prokaryotic cells or typical animal cells 5 Which row is correct for the structures present in typical plant cells and typical animal cells? cell structure plant cell animal cell A plasmodesmata present present B Golgi body present not present C centriole not present present D tonoplast not present not present 6 Which row is correct for cellulose? rotation of alternate shape of molecule hydrogen bonds between molecules A 3 branched 7 key B 7 branched 3 3 = present C 7 unbranched 7 7 = not present D 3 unbranched 3 7 Which statements about peptide bond formation are correct? 1 The bond formation occurs between a carbon of one amino acid and a nitrogen of the next amino acid after the amino acids detach from tRNA. 2 The bond formation occurs at the ribosome while the amino acids are still attached to tRNA, and is a hydrolysis reaction. 3 The bond formation is important for growth of an organism and when the bond forms, a water molecule is removed. A 1 and 3 B 2 and 3 C 2 only D 3 only

The diagram shows naturally occurring D-glucose and a form of glucose that can be synthesised in the laboratory, known as L-glucose. D-glucose L-glucose2OH2OH The enzyme glucose oxidase catalyses the oxidation of D-glucose. The enzyme cannot catalyse the oxidation of L-glucose. Which statement about L-glucose explains this? A L-glucose does not fit into the active site of glucose oxidase. B L-glucose has a different structural formula to D-glucose. C L-glucose is a synthetic sugar. D L-glucose is the mirror image of D-glucose. [Turn over

Tests for biological molecules were carried out on three solutions. Each solution contained only one type of biological molecule. The observations were as follows. solution test observation 1 Benedict's test blue to orange 2 Benedict's test after acid hydrolysis blue to red 3 biuret test blue to purple Which solutions would contain either sucrose or amylase? A 1, 2 and 3 B 1 and 3 only C 2 and 3 only D 2 only

Which row describes the expected effect on V max and Km when a competitive reversible inhibitor is added to an enzyme-catalysed reaction? effect on Vmax substrate concentration at K A no change increases B no change no change C decreases increases D decreases no change

The graph shows the effect of substrate concentration on the rates of reaction of three enzymes, X, Y, and Z. 2500 2000 1500 1000 rate of reaction product per second 0 200 400 600 substrate concentration / μmol dm 800 1000 1200 enzyme X enzyme Z enzyme Y What is the correct order of affinity of these enzymes for their substrates, starting with the enzyme with the highest affinity?

Which row correctly identifies the weak and strong bonds in the tertiary and quaternary structure of a typical protein? type of bond disulfide hydrogen hydrophobic ionic A strong strong weak weak B strong weak weak weak C weak weak strong strong D weak weak weak strong [Turn over

Which row correctly describes haemoglobin? four polypeptide chains, each containing a haem group iron ions can oxygen, forming oxyhaemoglobin in each chain, hydrophobic R-groups of amino acids point towards the centre of the molecule at 50% saturation, two oxygen molecules are transported by the molecule polypeptide chains interact to produce a globular chain each chain contains a haem group of amino acids surrounding an iron ion consists of two identical alpha chains and two identical beta chains each chain can transport an oxygen molecule polypeptide chains interact to produce an almost spherical molecule an iron ion is present within each haem group quaternary structure has two alpha chains and two beta chains each molecule can transport a total of four oxygen atoms polypeptide chains produce a loose helical shape, which folds to form a spherical molecule iron ions in the molecule can bind reversibly with oxygen in each chain, hydrophobic R-groups of amino acids surround the iron ion each molecule can transport a total of eight oxygen atoms

Which process always takes place without the involvement of energy from ATP? A active transport B endocytosis C exocytosis D facilitated diffusion

The diagram shows the entry of molecule X into a cell. molecule X Which row shows a property of molecule X and the effect of the concentration of ATP in the cytoplasm on the rate of entry of molecule X? property of molecule X concentration of ATP in the cytoplasm A non-polar affects rate of entry of molecule X B non-polar has no effect on rate of entry of molecule X C polar affects rate of entry of molecule X D polar has no effect on rate of entry of molecule X [Turn over

The electron micrograph shows some human blood cells. Which row correctly shows the net movement of water by osmosis and the water potential of the cytoplasm of cell X compared with the solution surrounding the cells? net movement of water by osmosis water potential of cytoplasm of cell X compared with the solution A into the cell higher B into the cell lower C out of the cell higher D out of the cell lower

A red indicator solution was mixed with agar and the resulting solid was cut into small cylindrical blocks. The blocks were placed in an acid which turns the indicator yellow and all other variables were kept constant. The dimensions of the blocks are shown. block 1 height 3 mm diameter 6 mm block 2 height 6 mm diameter 12 mm block 3 height 8 mm diameter 16 mm . The formula for Which row shows the correct surface area (SA) to volume (V) ratio for each block and the time taken for the block to turn yellow? block 1 block 2 block 3 SA to V ratio time to turn yellow / mins SA to V ratio time to turn yellow / mins SA to V ratio time to turn yellow / mins A 0.75 : 1.0 4 1.5 : 1.0 5 2.0 : 1.0 11 B 0.75 : 1.0 11 1.5 : 1.0 5 2.0 : 1.0 C 1.33 : 1.0 4 0.67 : 1.0 5 0.5 : 1.0 11 D 1.33 : 1.0 11 0.67 : 1.0 5 0.5 : 1.0

Which metabolic processes will be very active in a cell that has just completed cytokinesis? 1 ATP formation 2 DNA replication 3 protein synthesis A 1, 2 and 3 B 1 and 3 only C 2 only D 3 only [Turn over

The diagram shows a typical mitotic cell cycle and the point in the cell cycle that has been reached by each of four cells, V, W, X and Y. 2 phase 1 phase S phase mitosis cytokinesis Which row correctly identifies the cells that match the two descriptions? DNA replication is complete but the cell has not yet reached its maximum size preparation for microtubule formation is nearly complete but chromosomes have not yet condensed A V X B W Y C V Y D W X

The graph shows the mean length of the spindle fibres during mitosis. Which region of the graph shows when all the centromeres have detached from the spindle fibres? time mean length of spindle fibres

The mRNA codons ACU, ACC, ACA and ACG all code for the same amino acid, threonine. Which anticodons could specify an amino acid other than threonine? 1 UCA 2 ACC 3 UGU 4 UGC A 1, 3 and 4 B 1 and 2 C 2 and 3 D 3 and 4 only

Which bond formation does DNA polymerase catalyse? A hydrogen bonds between bases B hydrogen bonds between nucleotides C phosphodiester bonds between bases D phosphodiester bonds between nucleotides [Turn over

In eukaryotes, the RNA molecules formed during transcription are modified by the removal of non-coding sequences. This is followed by the joining together of coding sequences to form mRNA. What are the coding sequences also called? A codons B exons C introns D primary transcripts

Which row correctly identifies sinks for sucrose transported by mass flow in plants? root storage organ growing leaf bud growing shoot tip A 3 3 3 key B 3 7 3 3 = sink C 7 3 7 7 = not a sink D 7 7 3

The diagram shows a transverse section through a transport tissue in a plant. Which row correctly identifies cell 1 and cell 2? cell 1 cell 2 A companion cell phloem sieve tube element B companion cell xylem vessel element C phloem sieve tube element phloem sieve tube element D phloem sieve tube element xylem vessel element

Which statement correctly describes the movement of solutes in the symplast pathway? A Cell surface membranes regulate the selective absorption of solutes into the symplast pathway. B Plasmodesmata control the movement of solutes from the symplast pathway to the apoplast pathway. C The symplast pathway transports dissolved mineral ions from the soil that cannot be transported by the apoplast pathway. D The movement of solutes through plasmodesmata in the symplast pathway is prevented in the endodermis by suberin.

Which statement helps to explain why water molecules are forced to move through xylem vessel elements as a consequence of transpiration? A Water molecules form hydrogen bonds with cellulose in the walls of xylem vessel elements in a process known as adhesion. B Water molecules form hydrogen bonds with neighbouring water molecules in a process known as cohesion. C Water molecules form ionic bonds with dissolved mineral ions, which helps to keep the water molecules together in a continuous column. D Water has a high latent heat of vaporisation and this prevents the evaporation of water in the xylem vessel elements.

The diagram shows the internal structure of the mammalian heart. Which letter identifies the location of the atrioventricular node? [Turn over

The diagram shows pressure changes in the left side of the heart during the cardiac cycle. 0 0.2 0.4 0.6 0.8 pressurekPa time/ s left ventricle aorta left atriumkey What happens in the heart at X? A The atrioventricular valves close. B The atrioventricular valves open. C The semilunar valves close. D The semilunar valves open.

Which components of blood are present in tissue fluid? phagocytes some proteins sodium ions A 3 3 3 key B 3 7 7 3 = present C 7 3 3 7 = not present D 7 3 7

In the lungs, movement of dissolved carbon dioxide out of the capillaries occurs in one of two ways: What is the minimum number of times that a carbon dioxide molecule that has been transported to the lungs in a red blood cell must cross a cell surface membrane to reach an air space in an alveolus? A 2 B 3 C 4 D 5

What maintains the steep concentration gradients needed for successful gas exchange in the lungs? 1 Air flow in the alveoli is in the opposite direction to blood flow in the capillaries. 2 Blood arrives in the lungs with a lower oxygen concentration and a higher carbon dioxide concentration than the air in the alveoli. 3 Blood is constantly flowing through and out of the lungs, bringing a fresh supply of red blood cells. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Where is cartilage tissue always found in the human gas exchange system? A in the trachea only B in the bronchi only C in the bronchioles and trachea D in the bronchi and trachea

Scientists compared the density of goblet cells in the lungs and the density of mucus in the lungs of three groups of people: The results are shown in the table. group goblet cell density cells per mm mucus density / arbitrary units non-smokers 19 smokers who do not have lung disease 54 26 smokers with lung disease 37 15 What is indicated by these data? 1 There is a positive correlation (relationship) between density of goblet cells and density of mucus. 2 Lung disease results in an increase in goblet cell density. 3 There is an association between tobacco smoking and an increase in mucus density. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only [Turn over

Which disease does Mycobacterium bovis cause? A cholera B HIV / AIDS C malaria D tuberculosis

An antibiotic inhibits the formation of cross-links between the molecules that form cell walls in bacteria. Which statements explain why bacteria are killed by the antibiotic? 1 The bacterial cell is destroyed by osmotic lysis. 2 Cellulose molecules cannot form hydrogen bonds. 3 The cell wall is no longer partially permeable. A 1 and 2 only B 2 and 3 only C 1 only D 2 only

Scientists investigated the effect of increasing concentrations of an antibiotic on the development of antibiotic resistance in bacteria. The scientists grew four groups of bacteria and added a different concentration of antibiotic to each group. The number of resistant bacteria and the total population of bacteria were measured at intervals for 24 hours for each group. The graphs show the results. 036912 time / hours antibiotic concentration = 0 mg dm 15 18 21 24 036912 time / hours antibiotic concentration = 90 mg dm 15 18 21 24 036912 time / hours antibiotic concentration = 215 mg dm 15 18 21 24 036912 time / hours antibiotic concentration = 600 mg dm 15 18 21 24key total population resistant population population of bacteria × 10 population of bacteria × 10 population of bacteria × 10 population of bacteria × 10 Which statements are correct conclusions that can be made from the results of this investigation? 1 Increasing the concentration of antibiotic decreases the population of non-resistant bacteria at the end of 24 hours. 2 The proportion of antibiotic-resistant bacteria increases with increasing concentrations of antibiotics. 3 Increasing the concentration of antibiotic always increases the number of resistant bacteria. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

What is the correct sequence of events in a primary immune response? B-lymphocyte differentiation

Which statement about the properties of the antigen-binding sites in different antibody molecules is correct? A They are located on the light chains only. B They have a hinge region to give flexibility for different antigens. C They have binding sites for receptors on phagocytes. D They have variable amino acid sequences for different antigens.

The diagram shows a stage in monoclonal antibody production. cancer cells hybridoma cells What is represented by X? A T-lymphocytes B B-lymphocytes C antigens D antibodies Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge.