2022 SASS Bio 4E MYE P2

Mid-Year Examination 2022/4Exp/Biology 3 [Turn over Section A [50 marks] Answer all the questions in the spaces provided. 1 Fig. 1.1 shows some of the ways in which proteins in our diet may be utilised in the body. Fig. 1.1 A B C D D

Mid-Year Examination 2022/4Exp/Biology 4 (a) Name the processes labelled A to D in Fig. 1.1. A…………………….………… C…………………….………… B…………………….………… D…………………….………… [2] (b) Name two enzymes found in the small intestine that aid in process A. ……..………………………………..……..…………………………….… [2] (c) Describe how process B takes place in the small intestine with reference to movement of substances. ……….………………………………………………………………………… ……….………………………………………………………………………… ……….………………………………………………………………………… …………..……………………………………………………………….… [2] (d) One of the arrows in Fig. 1.1 represents a process carried out by living organisms to release energy. (i) On Fig. 1.1, label the arrow with the name of the process. [1] (ii) State the word equation for the process. ……..……………………………………………………………… [1] (e) Suggest what would happen to the cells of the body if excess water was not removed during process D. ……….………………………………………………………………………… ……….………………………………………………………………………… ……….………………………………………………………………………… …………..……………………………………………………………….… [2] [Total: 10]

Mid-Year Examination 2022/4Exp/Biology 5 [Turn over 2 Spirometry is a common breathing test that measures the volume and speed at which air is inspired and expired by the lungs. Fig 2.1 is a graph known as a spirogram, which shows the changes in air flow through a healthy person’s lungs over a period of time. Fig. 2.1 (a) Using Fig. 2.1, calculate the maximum volume of air the person can expire after he takes a deep breath. Show your working clearly. ……..…………………………… ……..…………………………….… [1] (b) Describe the mechanism that brings about expiration of air. ……….………………………………………………………………………… ……….………………………………………………………………………… ……….………………………………………………………………………… ……….………………………………………………………………………… …………..……………………………………………………………….… [3] normal breathing vigorous exercise maximum lung volume 0 4 8 12 16 20 24 28 32 100 104 108 112 T U V W X 5000 4000 3000 2000 1000 0 volume of air in lungs /cm3 time/seconds

Mid-Year Examination 2022/4Exp/Biology 6 (c) The person engaged in vigorous exercise from time V to W. Complete the graph in Fig 2.1 to show the volume and speed at which air is inspired and expired by the lungs from W to X. [1] (d) Suggest how the spirogram might differ for an individual that suffers from chronic bronchitis. ……….………………………………………………………………………… …………..……………………………………………………………….… [1] [Total: 6] 3 Non-disjunction refers to the failure of homologous chromosomes or sister chromatids to separate properly during cell division. When non-disjunction occurs, it results in a change in chromosome number in cells. (a) Suggest a human disease that might result from non-disjunction. Explain your ans