EXAMINATIONS COUNCIL OF SWAZILAND Swaziland General Certificate of Secondary Education CANDIDATE NAME CENTRE NUMBER CANDIDATE NUMBER BIOLOGY 6884/02 Paper 2 Core October/November 2016 1 hour 15 minutes Candidates answer on the Question Paper. No additional materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen in the spaces provided on the Question Paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Do not write on the barcode. Answer all questions. You may use an electronic calculator. You may lose marks if you do not show your working or if you do not use appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. 1 2 3 4 5 6 7 8 Total This document consists of 14 printed pages and 2 blank pages. ECOS 2016 [Turn over
1 (a) Fig. 1.1 shows leaves of different plants. 2 A D E C B Fig. 1.1 (i) the key below to identify the plants. Write their names in the spaces below. 1 2 3 4 has leaflets go to 2 has no leaflets go to 3 has 3 leaflets Rosa persica has more than 3 leaflets Carica papaya has rough margins Lantana camara has smooth margins go to 4 pair of veins from same origin on main vein Persea americana veins from alternating points on main vein Mangifera indica A... B... C... D... E... [4] (ii) All the leaves in Fig. 1.1 belong to plants of the same group. State two visible features of the leaves in Fig 1.1 which identify the group to which the plants belong. 1... 2... [2]
(b) The scientific name for the house mouse is Mus musculus. 3 State what each of the two terms in the name of the mouse represents, with reference to the binomial system of naming organisms. Mus musculus... [2] [Total: 8] [Turn over
4 2 Fig. 2.1 shows a cell F taken from a leaf of a dicotyledonous plant G that has wilted due to excessive use of artificial fertilisers. H excessive nitrates in the soil F G Fig. 2.1 (a) (i) Name the cell structure labelled H in Fig. 2.1.... [1] (ii) Label the nucleus of the cell in Fig. 2.1, using the letter J and a label line. [1] (iii) Describe and explain the effects of excessive use of artificial fertilsers on the plant and its cells in Fig. 2.1.... [4] (b) Fertilisers contain nitrates. State the importance of nitrates in plants.... [1]
(c) Photosynthesis takes place in the leaves. 5 (i) Describe how plants obtain carbon dioxide and water needed for photosynthesis. carbon dioxide... water... [4] (ii) Define the term translocation.... [3] [Total: 14] [Turn over
6 3 (a) Energy released during respiration is used in a number of ways in the body. State two uses of the energy released during respiration in the body. 1... 2... [2] (b) An athlete competes in a 5000 m race. (i) State a nutrient that is required in high concentration in the blood of the athlete during the race.... [1] (ii) Describe what happens to the rate and depth of breathing of the athlete during the race.... [1] (c) Table 3.1 shows the concentration of carbon dioxide and oxygen in inspired and expired air. Table 3.1 % in inspired air % in expired air carbon dioxide 0.04 4 oxygen 21 16 Explain the differences in carbon dioxide and oxygen concentration between the inspired and expired air. carbon dioxide......... oxygen......... [3]
7 (d) Fig. 3.1 shows the human respiratory system. alveoli Fig. 3.1 (i) Label the trachea using a label line and the letter K on Fig. 3.1. [1] (ii) List two features of the alveoli that make it efficient for gaseous exchange. 1... 2... [2] (e) Tobacco smoke contains tar and other harmful chemicals. Describe the effects of tar on the respiratory system............. [2] [Total: 12] [Turn over
8 4 The skin has a homeostatic function in the human body. Fig. 4.1 shows the structure of the skin. (a) Define the term homeostasis. Fig. 4.1...... [2] (b) Describe the roles of structures L, M and N in regulating the body temperature when it is cold. L......... M......... N......... [6] [Total: 8]
9 5 Mendel carried out an experiment to study the inheritance of some characteristics in peas. (a) State the term used in genetics to describe the visible characteristics of an organism.... [1] (b) In one of the experiments, he crossed peas that had wrinkled seeds with those that had smooth seeds. Offspring from the crossed peas produced 50% wrinkled seeds and 50% smooth seeds. The allele for wrinkled seeds (r) is recessive to the allele for smooth seeds (R). Complete the genetic diagram to show how the offspring with 50% wrinkled seeds and 50% smooth seeds was produced. parents: X parental genotype: gametes: crosses: offspring genotype: Rr Rr rr rr [4] (c) Humans in a population may have the blood groups A, B, AB or O. (i) Name the type of variation shown by human blood groups.... [1] (ii) Name the cause of this type of variation.... [1] (d) Mutation is a source of variation. State two factors that may increase the rate of mutation in organisms. 1... 2... [2] [Total: 9] [Turn over
10 6 (a) Fig. 6.1 shows a graph of the thickness of the uterus lining of a woman from the 10th of April to 10th of May 2016. thickness of uterus lining/ arbitrary units 7 6 5 4 3 2 1 0 10 15 20 25 30 05 10 April May calendar dates Fig. 6.1 (i) State what Fig. 6.1 shows is happening in the body of the woman between the 10th and 13th of April.... [1] (ii) Describe two features of the woman s menstrual cycle, between the 21st and 26th of April, which makes this her fertile period. 1... 2... [2] (iii) Describe what would happen to the thickness of the uterus lining on the 7th of May, if the woman got pregnant.... [1] (b) State the role of oestrogen in the menstrual cycle.... [1] (c) Describe the main stages of birth................ [3]
11 (d) Unwanted pregnancies can be prevented by using different methods of birth control. (i) Name and describe the surgical method of birth control in males.... [2] (ii) Describe a mechanical method of birth control which also prevents the transmission of HIV.... [2] [Total: 12] [Turn over
7 (a) Define the term habitat. 12...... [2] (b) The organisms listed in the box are found in an ecosystem. eagle grass impala egret caterpillar (i) Complete the food web in Fig. 7.1 using only organisms selected from the list in the box. vulture (i)... Food chain 1 (ii)... Food chain 2 (iii)... (iv)... Fig. 7.1 [3] (ii) Explain an advantage to the vulture of food chain 2 over food chain 1.... [2] (c) In the carbon cycle, carbon circulates between the atmosphere and living organisms. State two ways by which carbon is returned to the atmosphere. 1... 2... [2] [Total: 9]
13 8 Fig. 8.1 shows a representation of the flow of water in a plant, not drawn to scale. T S P R soil Fig. 8.1 (a) Name the microscopic structure through which water enters the root at P.... [1] (b) Describe how the xylem vessels are adapted to transport water in R.......... [2] (c) Describe the movement of water from the leaf xylem at S to the atmosphere............. [3] [Turn over
14 (d) Describe how humidity and temperature affect the rate of water loss from S to T. humidity...... temperature...... [2] [Total: 8]
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