BIOLOGY HIGHER LEVEL

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1 *P14* PRE-LEAVING CERTIFICATE EXAMINATION, 2008 BIOLOGY HIGHER LEVEL TIME: 3 HOURS Section A. Answer any five questions from this section. Each question carries 20 marks. Write your answers in the spaces provided on this examination paper. Section B Answer any two questions from this section. Each question carries 30 marks. Write your answers in the spaces provided on this examination paper. Section C Answer any four questions from this section. Each question carries 60 marks. Write your answers in the answer book. It is recommended that you spend not more than 30 minutes on Section A and 30 minutes on Section B, leaving 120 minutes for Section C. You must return this examination paper with your answer book at the end of the examination. Page 1 of 10 [OVER

2 Section A Answer any five questions. Write your answers in the spaces provided. 1. Answer five of the following by filling in the blank space. (a) (d) (e) (f) The Eustachain tube connects the pharynx and the An organism whch reproduces by budding is Intercoastal muscles function in the process of. Amoeba gets rid of excess water through the Peristalsis is defined as The connects the liver with the small intestine. 2. Answer the following questions in relation to the endocrine system. A B Name the two endocrine glands labelled. A B What is the function of the gland labelled B? What is a hormone? On the diagram label X where the pituitary gland is located. Name one hormone the pituitary gland secretes. Page 2 of 10

3 3. Answer the following parts in relation to the diagram. D Free Nitrogen A Nitrates Plant Protein B Animal Protein D Death Nitrites Ammonia C (a) (d) (e) (f) (g) What term is used to describe the events shown in the diagram? What is process A? State one way in which nitrates enter the root hairs of plants. What form of nutrition is involved in process B? What is process C? Name two groups of organisms responsible for process C. What is process D? 4. Answer the following questions (a) (d) (e) Name an anabolic reaction. Name two dissolved salts.. Define organisation What is the purpose of a control? What is a theory? Page 3 of 10 [OVER

4 5. Distinguish clearly between the following pairs of terms. (a) Prokaryote and Eukaryote Mitochondria and Chloroplast Nucleus and Nucleolus (d) Organ and Tissue (e) Diploid and Haploid 6. What is genetic screening? What is a gene? State two differences between D.N.A. and R.N.A. in the table below. D.N.A. R.N.A. What bonds holds the bases together? Name the two purine bases. Page 4 of 10

5 Section B Answer any two questions. Write your answers in the spaces provided. Part (a) carries 6 marks and part carries 24 marks in each question in this section. 7. (a) Answer the following in relation to human breathing rate OR pulse rate & heart dissection. What is the average rate at rest? Suggest a relationship between recovery time and a person s degree of physical fitness. (i) Describe how you would investigate the effect of exercise on this rate. (ii) Describe how you dissected a mammalian heart in order to investigate the internal structure of atria and ventricles. (iii) State the procedure that you followed to expose a semilunar valve. (iv) Why has one chamber of the heart more muscle in its wall? Page 5 of 10 [OVER

6 8. (a) Enzymes act as catalysts to metabolic reactions. They usually show a high degree of specificity in respect to their substrates. Define the underlined terms. Specificity Substrates Answer the following by reference to an experiment that you carried out to investigate the effect of heat denaturation on the activity of an enzyme. (i) What is an enzyme? (ii) (iii) (iv) Name the enzyme used Name the substrate State how you varied temperature (v) (vi) Name a factor you kept constant. How did you keep this factor constant? (vii) State the results of the experiment Page 6 of 10

7 9. (a) Name a structural protein State the general formula for carbohydrates Answer the following questions in relation to the food tests. (i) (ii) Name a reducing sugar Name the reagent(s) used to test for a reducing sugar Fill in the table below in relation to a test for a reducing sugar. Initial colour of reagent Final colour of reagent Is heat required (iii) Name the reagents used to test for the presence of protein in a food State the colour it goes for a positive result (iv) Describe how you carried out a test for starch Page 7 of 10 [OVER

8 Section C Answer any four questions. Write your answers in the answer book. 10. (a) (i) Define excretion. Why is egestion not a form of excretion? (ii) Where are nitrogenous excretory substances made in the human body? (9) The production of urine in the nephron involves filtration and reabsorption. (i) State where filtration occurs in the nephron. (ii) State where glucose is reabsorbed in the nephron. (iii) Account for the development of the filtration pressure. (iv) What process is involved in the reabsorption of water? (v) State a function of the kidneys other than excretion. (vi) Name a hormone that is involved in water balance. State precisely where its made. (27) What is an ectotherm? Answer the following in relation to human skin. (i) Name the outer layer. (ii) The skin has protective roles in relation to U.V. light and infection. How does the skin protect against U.V. light? How does the skin protect against infection? (iii) Name two substances excreted by means of the skin. (iv) State a role of hair other than its involvement in insulation. (v) Name a vitamin which is manufactured in the skin. (24) 11. (a) Explain the following ecological terms: ecological pyramids, niche, symbiosis. (9) (i) List three plants and three animals present in the ecosystem you studied. (ii) State two ways how a named animal or a named plant listed in part (i) is adapted to its habitat. (iii) The capture/recapture method is one of the ways by which the number of an animal species in the ecosystem may be estimated. Outline for any named animal, how you would carry out the following stages of the method: The initial capture of the animals: The tagging/marking of the animals: The release of the tagged/marked animals: The use of the figures which you obtained to determine the approximate number of the animal present in that ecosystem. (27) Answer the following in relation to energy flow through an ecosystem. (i) Name the process by which this energy is converted to a form which all living organisms can use. (ii) What is the approximate percentage loss of energy at each stage within the ecosystem? (iii) State the significance of the loss of energy at each transfer stage to (a) the length of food chains the number of organisms at the final trophic level. Describe using words and/or labelled diagrams the events of the carbon cycle. (24) Page 8 of 10

9 12. (a) (i) Give a balanced chemical equation to summarise aerobic respiration. (ii) Name the polysaccharide storage material in mammals from which glucose is produced for respiration. (9) The diagram shows an outline of some of the events in the complete aerobic respiration of glucose in a cell. (i) Name stage A and stage B. (ii) State where in the cell each Polysaccharide of these stages takes place. Storage material (iii) Describe the main features of stage B. { Stage A PYRUVIC ACID GLUCOSE PYRUVIC ACID { Stage B ACETYL COENZYME A Cycle of Reactions (27) Yeast cells produce ethanol (alcohol) in a process called fermentation. (i) Name a substance that yeast can use to make ethanol. (ii) What substance other than ethanol is produced during fermentation. (iii) How did you know when fermentation was finished? (iv) Give an account of a chemical test to demonstrate that alcohol (ethanol) has been produced. Include the initial colour and final colour of the test. (24) 13. (a) Explain briefly the role of DNA in heredity. (9) Variation may result from mutation (i) Explain the underlined terms. (ii) Comment on the validity of the statement above. (iii) State two agents responsible for mutation. (iv) Other than mutation how else could variation be brought about? (27) What is evolution? Give an account of the theory of natural selection. Name the scientists who are associated with the theory. (24) Page 9 of 10 [OVER

10 14. Answer any two of (a), and. (a) (i) State two ways in which a bacterial cell differs from a typical plant cell. (ii) Name two human diseases for which bacteria are responsible. (iii) State how parasitic bacteria can survive for long periods outside the host s body. (iv) State a role of parasitic bacteria in the overall scheme of nature. (v) Distinguish between the term s antigen & antibiotic. (vi) Name three factors that affect the growth of bacteria. (i) Give the meaning of the term vegetative propagation. (ii) Name two natural methods of propagation. (iii) Name two artificial methods of propagation. (iv) Give an illustrated account of how vegetative propagation takes place in a named plant. (v) Give two disadvantages and one advantage of this type of reproduction in plants. Most seeds pass through a dormant period before germination. (i) Explain the underlined terms. (ii) State one advantage of the dormant period. (iii) Give a detailed account of what happens during germination. (iv) Describe an experiment to demonstrate that oxygen is essential for germination. (30, 30) 15. Answer any two of (a), and. (a) (i) Contrast the structure of arteries and veins in transverse section by use of labelled diagrams. (ii) Give reasons for any two differences in structure of arteries and veins. (iii) Write an informative note on one of the following: Hepatic portal vein Lymph nodes Red blood cell. (i) Apart form sight and hearing, name two other senses. (ii) Draw a large labelled diagram of the ear. (iii) Name the three tiny bones found in the middle ear. (iv) Is the inner ear filled with Air or Fluid? (v) Give the function of the following parts of the eye retina and lens. (i) Draw a large labelled diagram of the human female reproductive system. (ii) Indicate clearly on your diagram where (i) fertilisation (ii) implantation takes place. (iii) Define ovulation and implantation. (iv) Give a function of FSH and a function of LH in relation to the menstrual cycle. (30, 30) Page 10 of 10

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