Biology Past Questions and Answers

The table below shows the percentage composition of fat and protein in six different meat types. Study it and answer questions 2(a) to 2(d).<br/><table class='tbn'><tbody><tr><td> <b>Meat Type</b> </td><td> <b>Fat (%)</b> </td><td> <b>Protein (%)</b> </td></tr><tr><td> A </td><td> 07.2 </td><td> 21.3 </td></tr><tr><td> B </td><td> 25.3 </td><td> 10.6 </td></tr><tr> <td> C </td><td> 20.0 </td><td> 22.5 </td></tr><tr><td> D </td><td> 03.1 </td><td> 28.2 </td></tr><tr><td> E </td><td> 12.6 </td><td> 17.3 </td></tr><tr><td> F </td><td> 13.2 </td><td> 14.3 </td></tr></tbody></table><br/><br/><br/>a. (i) Which <b>two </b>of the meat types may be recommended for an obese patient? [2 marks]<br/> (ii) State <b>one </b>reason for the answer in 2(a)(i). [1 mark]<br/>b. (i) Which <b>two </b>of the meat types would provide the most energy? [2 marks]<br/> (ii) State <b>two</b> reasons for the answer in 2(b)(i). [2 marks]<br/>c. (i) Which <b>three </b>of the meat types could be recommended for a child suffering from kwashiorkor? [3 marks]<br/> (ii) State <b>one </b>reason for the answer in 2(c)(i) [1 mark]<br/>d. Which of the meat types would most likely be suitable for:<br/> (i) an active teenager; [1 mark]<br/> (ii) a 70-year old human? [1 mark]<br/>e. Which other class of food provides energy? [1 mark]<br/>f. State <b>three </b>uses of fat in the human body. [3 marks]<br/>g. Describe briefly the procedure for testing for fat in a meat sample using a piece of white paper. [3 marks]<br/>

a. Classify the following biological associations under the headings in the table below:<br/> (i) Remora and shark;<br/> (ii) Lichen;<br/> (iii) Cattle and white Egret;<br/> (iv) Tapeworm in the gut of humans;<br/> (v) Flowers and Honeybees; <br/> (vi) Mistletoe and Cacao plant.<br/><table class='tbn'><tbody><tr><td> Parasitism </td><td> Mutualism </td><td> Commensalism </td></tr><tr><td> </td><td> </td><td> </td></tr></tbody></table><br/><br/><br/><br/> [6 marks]<br/>b. (i) State <b>three </b>adaptive features of parasites. [6 marks]<br/> (ii) State <b>two </b>effects of parasites on their hosts. [2 marks]<br/>c. (i) What are saprophytes? [2 marks]<br/> (ii) Give <b>four </b>examples of saprophytes. [4 marks]

Use the information below to answer questions (a)(i) and (a)(ii).<br/> Hb Are presents normal haemoglobin, <br/> HbS represents sickled haemoglobin.<br/> <br/>a. A female heterozygote for sickle cell married a sickler. With the aid of a genetic diagram, determine the: <br/> (i) possible genotypes of their offspring; [8 marks]<br/> (ii) phenotypic ratio of the offspring. [2 marks]<br/>b. Explain <b>briefly </b>the reason why a Rhesus negative woman married to a Rhesus positive man might lose her second pregnancy. [5 marks]<br/>c. Name <b>two </b>examples of features in animals that support the theory of use and disuse of body parts as used by Lamarck. [2 marks]<br/>d. List <b>three</b> structures in mammals that are vestigial. [3 marks]

a. Explain <b>briefly </b>the importance of the following factors and organisms in the nitrogen cycle<br/> (i) <i>lightning</i>; [3 marks]<br/> (ii) <i>Nitrosomonas</i>; [2 marks]<br/> (iii) <i>Azotobacter</i>. [2 marks]<br/>b. Name the excretory organ in:<br/> (i) insects: [1 mark]<br/> (ii) earthworm.<br/>c. Define<br/> (i) hepatitis; [4 marks]<br/> (ii) kidney stones [4marks]<br/>d. (i) State <b>three </b>effects of lack of sense receptors in the skin to humans. [3 marks]<br/> (ii) List <b>three </b>layers of the epidermis in the skin of humans. [3 marks]<br/>e. (i) What is <b><i>metamorphosis</i></b>? [2 marks]<br/> (ii) State the type of metamorphosis exhibited by <b>each </b>of the following insects listed in the table below.<br/><table class='tbn'><tbody><tr><td> <b>Insect</b> </td><td> <b>Type of metamorphosis </b> </td></tr><tr><td> Grasshopper </td><td> </td></tr><tr><td> Cockroach </td><td> </td></tr><tr><td> Butterfly </td><td> </td></tr><tr><td> Mosquito </td><td> </td></tr><tr><td> Housefly </td><td> </td></tr></tbody></table><br/><br/><br/><br/>

a. Complete the table below.<br/><table class='tbn'><tbody><tr><td> <b>Organism</b> </td><td> <b>Mode of feeding</b> </td><td> <b>Feature of mouthpart that adapts organism to mode of feeding</b> </td></tr><tr><td> </td><td> </td><td> </td></tr><tr><td> </td><td> </td><td> </td></tr><tr><td> </td><td> </td><td> </td></tr></tbody></table><br/><br/><br/> [6 marks]<br/> <br/>b. List five parts of the alimentary canal of an earthworm. [5 marks]<br/><br/>c. State six ways by which water could be polluted by agricultural practices. [6 marks]<br/><br/>d. Describe briefly the life cycle of a housefly. [5 marks]<br/><br/>e. Make a diagram, 6 cm – 8 cm long of the hypogeal germination in a mature maize seedling and label fully. [8 marks]<br/>