NAMIBIA SENIOR SECONDARY CERTIFICATE

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1 Centre Number Candidate Number Candidate Name NAMIBIA SENIOR SECONDARY CERTIFICATE BIOLOGY ORDINARY LEVEL 4322/2 PAPER 2 2 hours Marks Additional Materials: Ruler INSTRUCTIONS AND INFORMATION TO CANDIDATES Candidates answer on the Question Paper in the spaces provided. Write your Centre Number, Candidate Number and Name in the spaces at the top of this page. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use correction fluid. You may use a non-programmable calculator. Do not write in the margin. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question Total Marker Checker ORDINARY LEVEL 1 2 This document consists of 15 printed pages and 1 blank page Republic of Namibia MINISTRY OF EDUCATION MoE/DNEA [Turn over

2 2 1 There are an estimated 10 million different kinds of organisms, living on the earth today. These organisms are sorted by biologists into various groups. (a) (i) State the term that refers to the sorting of organism into groups. [1] (ii) Put the following names of the groups into the correct sequence, starting with the group that contains the most types of organism. class; family; kingdom; order [3] (b) Zebras belong to a group of organisms called mammals. Equus burchelli is a scientific name of one species of zebra. (i) State two externally diagnostic features of all mammals [2] (ii) State the species of zebra given above. [1] (iii) Explain what is meant by the term species. [1] [8]

3 3 2 Fig. 2.1 shows the transverse section through a portion of a leaf. A B C D E Fig. 2.1 (a) (i) Identify the cell structures labelled A and B. A... [1] B... [1] (ii) Identify the tissue labelled E. [1] (b) State the function of the tissue labelled D [1] (c) Name the substance found in the wall of cell C. (d) (i)... [1] State the process by which carbon dioxide gets into the leaf. [1] (ii) On Fig. 2.1, use labelled arrows to show how water and carbon dioxide get to one of the cell structures labelled B. [2] (e) Give a reason why leaves need to have a large surface area [1] [Turn over

4 (f) (i) 4 Name three factors that may limit the rate of photosynthesis of a healthy plant [3] (ii) Define the term limiting factor. [1] (g) Suggest why plants sometimes stop photosynthesising on very hot, dry days [1] [14]

5 5 3 Cereals are monocotyledonous plants and their seeds contain most of the nutrients needed for a healthy human diet. (a) With reference to the seed, distinguish between monocotyledonous and dicotyledonous plants [1] (b) (i) List three conditions needed for seed germination [3] (ii) Describe the role of the enzymes in the germination of seeds. [3] [Turn over

6 6 (c) Table 3.1 show the mass of some of the different food substances present in 100 g of different cereals. Table 3.1 cereal protein/g fat/g fibre/g available carbohydrate/g brown rice maize oats sorghum wheat (i) On the grid, draw a bar graph of the amount of fibre in the different cereals. [4]

7 7 (ii) 1 g of fat gives 37 kj of energy. the data from Table 3.1 to find the energy in fat in 100 g of maize. Show your working. [1] (iii) Describe the importance of fibre in the diet. [2] [14] [Turn over

8 8 4 Fig. 4.1 shows some of the organs and blood vessels involved with digestion, absorption and assimilation in the human body. A B C (a) (i) State the names of B and C. Fig. 4.1 B... [1] C... [1] (ii) C has two sections. Name one of these sections and state its function. Section name... [1] Function... [1] (iii) Name the enzyme that breaks down fats so that they can be absorbed. [1] (b) (i) Name three nutrients transported by B [3] (ii) Explain what happens in the organ labelled A when blood glucose concentration is below normal. [2] [10]

9 9 5 Fig. 5.1 shows two types of white blood cells. A B Fig. 5.1 (a) (i) Identify the blood cells A and B. A... [1] B... [1] (ii) Name one visible feature that is present, but different in blood cells A and B. [1] (iii) Describe the difference in the feature named in (a)(ii), between blood cell A and B. [1] (b) White blood cells play an important role in the body s immune system. Describe what is meant by natural immunity [4] [8] [Turn over

10 10 6 (a) (i) Distinguish between geotropism and phototropism. [2] (ii) A seedling was exposed to light from one side only and left for several days. Fig. 6.1 shows the seedling at the beginning and after several days. light seedling at beginning seedling several days later Fig. 6.1 Explain the appearance of the seedling after several days. [4]

11 11 (b) Fig. 6.2 shows a section through the human eye. Fig. 6.2 On Fig. 6.2, label each of the following with the appropriate letter and label line. (i) L - the area of the eye which contains light sensitive cells (ii) B - the structure that is responsible for most of the bending of the light (iii) A - the structure responsible for adjusting the amount of light entering the eye (iv) T - the structure which absorbs all the light after it has been through the inner layer of the eye [4] (c) Explain why the response of the eye to light is faster than the response of the seedling to light [3] [13] [Turn over

12 12 7 Fig. 7.1 shows a developing fetus inside the uterus. A B C Fig. 7.1 (a) Name the structures labelled A, B and C. A... [1] B... [1] C... [1] (b) (i) Name two useful substance which passes from the mother to the fetus [2] (ii) Name one waste substance that passes from the fetus to the mother. (c) (i) [1] The mother contracted gonorrhoea during pregnancy. List two symptoms of this disease [2] (ii) What medication could be prescribed to the mother to prevent the spread of the disease to the fetus? [1] (iii) State the method of birth control which can prevent the spread of gonorrhoea. [1] [10]

13 13 8 Humans release carbon dioxide during respiration. This carbon dioxide enters the atmosphere as part of the carbon cycle. (a) (i) State one human activity that increases the amount of carbon dioxide in the atmosphere. [1] (ii) During the carbon cycle, photosynthesis removes CO 2 from the atmosphere, to produce carbohydrates. Name the form in which these carbohydrates are stored in a plant. [1] (iii) Explain what happens to the carbon containing compounds in plants and animals when they die. [2] (b) Deforestation is one of the human activities that disrupt the process of photosynthesis. State three other undesirable effects of deforestation on the environment [3] [7] [Turn over

14 14 9 An ecosystem is made up of organisms that interact with each other and the environment in which they live. (a) (i) Name the primary source of energy in an ecosystem. [1] (ii) Explain why energy flow through an ecosystem is said to be non-cyclical. [2] (b) Explain why it is more efficient for humans to eat plants instead of feeding plants to cattle, goats or sheep [3]

15 15 (c) To survive, human beings need access to resources. Such resources need to be conserved. (i) Define the term conservation. [2] (ii) Describe four ways in which water can be conserved [4] (iii) Discuss two advantages of tourism for conservation in Namibia [2] (iv) Discuss two disadvantages of tourism for conservation in Namibia [2] [16]

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