7/27/2019 CAPE Biology Past Papers 2006 http://slidepdf.com/reader/full/cape-biology-past-papers-2006 1/8 l I i -2- SECTION A Answer ALL questions n this section.You must write your answers n the spaces rovided on the question paper. 1. (a) Carbohydratemoleculesmay be oined by either cror B linkages. FigureI shows2 glucosemolecules oined by an a-t-4 glycosidic inkage. CH" OH cH2 oll H C-OH HC-O OH \-/i v v; \./ /'\9" T/--.,rVt tll-\ HO C_C _ C-C H t! 6" it o" Figure 1. Two glucose molecules (i) Using an o-1-6linkage, attach a third glucose molecule in Figure 1. [ 2 marks] (ii) Name ONE example of a carbohydrate that is made up of components with BOTH ana-l-4 glycosidic linkage and an a,-1-6linkage. Ilmark] (iii) Distinguishbetweenan cr glycosidic inkage' anda 'B linkage'. Ilmark] Comment on the difference in function between a carbohvdrate with ct inkaees and a carbohydrate with B linkages. [ 2 marks] GO ON TO THE NEXT PAGE (iv) 22107020/CAPE/2008
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The pawpaw has male and female flowers which are borne on different plants.
(i) State the term used to describe this reproductive feature.
I lmark]
(ii) StateONE disadvantageto the plant in having this feature.
I lmark]
Plants can also be propagated non-sexually. Suggest TWO mechanisms thatoccur NATURALLY in plants to aid NON-SEXUAL propagation.
[ 2 marks]
(ii) StateONE advantage f the mechanisms ou identified n (c) (i).
I lmark]
Methods exist for the artificial propagation of plants utilizing small amounts of plantmaterials. Discuss THREE advantagesof these methods over the natural methods ofnon-sexual propagation.
(i) State the functions of EACH of the following in oogenesis in humans:
a) gonadotrophin releasing hormone
b) luteinising hotrmone
c) follicle stimulation hormone. [ 4 marks]
(ii) Explain how thesehormones function in males as compared to females.
[ 3 marks]
(b) The inhibition of the production of luteinising hormone and follicle stimulatrnghormone by oestrogen and progesterone is the basis of one contraceptive method infemales. Comment on why the same principles CANNOT be applied to develop amale hormonal contraceptive. [ 4 marks]
(c) In addition to similarities, differences exist between oogenesis and spermatogenesis.
Discuss TWO significant differences with respect to the timing of oogenesis andspeflnatogenesrs. [ 4 marks]