Cambridge A Level Biology 9700 — 2001 Oct/Nov Paper 2 · Variant 1

This question paper consists of 11 printed pages and 1 blank page. SB (SLC/KN) S11940/1 © CIE 2001 [Turn over CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Advanced Subsidiary Level BIOLOGY 8700/2 PAPER 2 OCTOBER/NOVEMBER SESSION 2001 1 hour Candidates answer on the question paper. No additional materials are required. TIME 1 hour INSTRUCTIONS TO CANDIDATES Write your name, Centre number and candidate number in the spaces at the top of this page. Answer all questions. Write your answers in the spaces on the question paper. All working for numerical answers must be shown. INFORMATION FOR CANDIDATES The intended number of marks is given in brackets [ ] at the end of each question or part question. Candidate Centre Number Number Candidate Name FOR EXAMINER’S USE 3 2 1 4 TOTAL 6 5

2 8700/2/O/N/01 1 Fig. 1.1 shows a three-dimensional diagram of part of a plant stem. Fig. 1.1 (a) Identify the structure labelled A and state one function it performs in the stem. … …[1] A B C For Examiner’s Use

3 8700/2/O/N/01 [Turn over (b) State three main structural features that help A to carry out this function. 1. … … 2. … … 3. … …[3] (c) The cell labelled B is involved in the transport of the products of photosynthesis up and down the stem. Identify the cell labelled C and explain how it is involved in this process. … … … …[3] [Total : 7] For Examiner’s Use

4 8700/2/O/N/01 2 Fig. 2.1 shows diagrams of two alveoli from the lungs of a smoker, A, and a non-smoker, B, after exhalation is complete. Fig. 2.1 (a) Identify the fibres labelled X, in Fig. 2.1, that surround the alveoli. …[1] (b) With reference to Fig. 2.1, explain why people who have smoked heavily for a long time often have difficulty in breathing and in obtaining sufficient oxygen. … … … …[3] X A B For Examiner’s Use

5 8700/2/O/N/01 [Turn over (c) State two pieces of epidemiological evidence and one piece of experimental evidence to link smoking with lung cancer. epidemiological evidence 1. … … 2. … … experimental evidence 1. … …[3] [Total : 7] For Examiner’s Use

6 8700/2/O/N/01 3 Fig. 3.1 is a diagram of part of an α helix of a polypeptide chain commonly found in many types of protein. Fig. 3.1 (a) (i) Name the repeating monomer of a polypeptide chain. …[1] (ii) Explain what would happen to the α helix if the polypeptide chain was heated to a temperature above 60 °C. … …[2] C C C C C C C C C C C C C C C C C C For Examiner’s Use

7 8700/2/O/N/01 [Turn over (b) In globular proteins, the polypeptide chain bends and folds to give a more compact shape. This is the tertiary structure of the protein. Name three types of bond that help to maintain the tertiary structure. 1. … 2. … 3. …[3] (c) Monosaccharides can also be linked together to form long chain molecules called polysaccharides. State two ways, other than the names of the monomers present, in which the structure of a polysaccharide chain differs from that of a polypeptide chain. 1. … 2. …[2] (d) The fibrous protein collagen and the polysaccharide cellulose both possess considerable tensile strength. List two features that contribute to the strength of (i) collagen; 1. … 2. …[2] (ii) cellulose. 1. … 2. …[2] [Total : 12] For Examiner’s Use

8 8700/2/O/N/01 4 Fig. 4.1 shows the process of translation occurring at a ribosome in a cell that synthesises enzymes that are secreted into the gut. Fig. 4.1 C C C A A A U U U U U U } } R P A G A S direction of movement of ribosome along mRNA growing protein molecule For Examiner’s Use

9 8700/2/O/N/01 [Turn over Table 4.1 shows some triplet base sequences of mRNA and the amino acids for which they code. Table 4.1 (a) With reference to Fig. 4.1 and Table 4.1, (i) name the amino acid P; …[1] (ii) state the base sequence at S; …[1] (iii) state the name given to the triplet base sequences on mRNA; …[1] (iv) describe the change that would occur to the protein if the base sequence at R was UUU instead of AUU. … …[1] (b) Describe what happens to the enzyme molecule after it has left the ribosome until it leaves the cell. … … … … …[4] [Total : 8] For Examiner’s Use mRNA amino acid AUU isoleucine AUC isoleucine AUG methionine UUU phenylalanine UCU serine CAU histidine

10 8700/2/O/N/01 5 Phagocytes are involved in removing bacteria from infected tissues. Fig. 5.1 is a drawing made from an electron micrograph of a phagocyte that has engulfed some bacteria. Fig. 5.1 (a) Name A to D. A … B … C … D …[2] (b) Explain why it would not be possible to see the same detail of a phagocyte, as shown in Fig. 5.1, using a light microscope. … … … …[3] (c) Explain how phagocytes engulf and destroy invading organisms, such as bacteria. … … … … …[4] [Total : 9] A B C D For Examiner’s Use

11 8700/2/O/N/01 6 (a) Complete Table 6.1 to show which of the four statements about the transmission and control of disease apply to cholera, malaria, HIV/AIDS and tuberculosis (TB). In each box, use a tick (✓) to show that the statement applies and a cross (✘) if it does not. Table 6.1 [4] (b) Sickle cell anaemia is an inherited disease that is common in areas of the world where malaria is endemic. Explain why sickle cell anaemia is common in areas where malaria is endemic. … … … … …[3] [Total : 7] For Examiner’s Use statement cholera malaria HIV/AIDS TB causative organism is a bacterium causative organism is water-borne transmitted by an insect vector sexually transmitted