Botany module 

 

QUESTION 1 1.1 Discuss the genetic regulation of the formation of nodules. (10) 1.2 Describe how the adaptation of perennial desert plants to arid conditions differs from those of desert annuals. (10) 1.3 Explain the concept "entropy" and state how it is related to enthalpy and free energy (5) [25] QUESTION 2 2.1 Explain four ways in which enzyme-catalyzed reactions differ from ordinary chemical reactions. (10) 2.2 The chlorophylls and carotenoids occur principally in the cell membranes, whereas the anthocyanins occur in the vacuoles. What does this distribution tell you about the chemical composition of these pigments? (15) [25] QUESTION 3 3.1 Discuss the possible benefits of photorespiration. (5) 3.2 Explain with the aid of appropriate equations why photosynthesis is a redox (oxidation-reduction) process. (10) 3.3 Describe the different parameters of light and state how it can be measured. (10) [25] QUESTION 4 4.1 Name the various chemical compounds in which nitrogen is exported from the bacteroid to the rest of the plant. (10) Tot 4.2 Explain the structure and composition of nitrate reductase, and the role of the enzyme in nitrate assimilation. (15) [25] TOTAL: 100 Marks