D it has been found that there are more individuals

This preview shows page 46 - 49 out of 200 pages.

(d) It has been found that there are more individuals suffering from XSCID than ADA SCID. Suggest possible explanations for this phenomenon. (line 9-12) (3) (e) State two differences in the biological consequences of “somatic gene therapy” and “germ-line gene therapy”. (line 13-18) (2) (f) In developed countries, people become more aware of the effects of smoking and alcoholism on the development of cancer. Discuss why cancer remains one of the top killer diseases in developed countries. (line 21-24) (5) (g) Besides cancer, state two other chronic diseases the risk of which can be reduced by sufficient daily intake of vegetables and fruits. (line 22-25) (2) 09 (IA) (2) Complete the following paragraph with suitable word(s). (5 marks)
47 10 (IC) (11) Read the following passage and answer the questions: (a) Why are subunit vaccines safer than traditional vaccines? (lines 2-6) (3) (b) Suggest two reasons to explain why the cost of producing subunit vaccines is usually much higher than that of traditional vaccines. (lines 3-7) (2) (c) Food vaccines in the form of edible parts of plants can be administered orally but subunit vaccines cannot. Why? (lines 19 -21) (4) (d) After being taken up into the bloodstream, how can the content of the food vaccines confer immunological protection to the individuals against a specific infectious disease? (lines 21-22) (4) (e) Suggest one advantage and one disadvantage of using bananas, instead of potatoes, as a food vaccine. (lines 23-25) (2)
48 Chapter 10 Evolution 91(I) (8) Evolutionary theory is supported by evidence from the following areas. Briefly describe how each has contributed to the support of the theory. (a) Selective breeding (b) Palaeontology (fossils) (6) 96 (II) (3) (b)(i) What is a species? (2) (ii) Name and describe the various isolation mechanisms which may lead to the formation of a new species. (7) 06 (IA) (8) (a) Suggest two ways in which scientists can make use of fossil records in their study of the evolutionary relationship of organisms. (2) (b) Suggest two limitations of using fossil records as evidence of evolution. (2) 07 (II) (2) To explain the diversity of life forms on Earth, Darwin proposed a theory that different species arose by gradual changes from ancestral stocks. It would be possible to identify the evolutionary relationship of different species by examining the similarities and differences between them and comparing them with pre-existing life forms. Evidence of evolution can be drawn from a wide range of sources, e.g. fossils, comparative anatomy, and comparative biochemistry. (a) (i) What are fossils? (2) (ii)

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture