Correct Answer: C. potassium

Explanation

(a) Classes of food other than carbohydrates are: protein, fats and oils / lipids, water, vitamins, mineral salts.

(b) The reasons why glucose is taken by an athlete before a race are: glucose is the simplest form of carbohydrate, i.e. soluble form of cabohydrate; which does not require any form of digestion. Hence, it is absorbed in the ileum, small intestine, where it diffuses and enters into the blood stream, circulatory system. It is then assimilated and oxidized; within the shortest time to give energy to the athlete. But corn meal is a complex carbohydrate, polysaccharide, starch, which will require series of carbohydrate / hyrolysis, starting from the mouth and later in the duodenum. Due to the processes, carbohydrate has to pass through it to the small intestine, ileum, which takes a longer time to produce energy for use, i.e cannot give immediate energy.

(c) To test for starch, obtain tuber of yam, cassava, potato, sweet potato, maize, cereal or any starchy food and macerate (crush). Then, add water to the mash to prepare starch solution; put a few drops of the starch (mashed material or a bit of the macerate on a white tile) test tube or watch glass. Add one to two drops of iodine and the material or solution will turn blue black, or black indicating presence of starch.

Correct Answer: C. ascorbic acid

Correct Answer: C. four slices of yam and stew, two pieces of beef, one cup of tea with milk and two oranges

Correct Answer: B. gene

Correct Answer: C. scurvy

Correct Answer: A. Asexually reproduced cells held together in a mass, but independent of each other

Correct Answer: A. Helps to regulate the acid-base balance of the body

Correct Answer: C. becomes a seed

Explanation

(a)(i) The four levels of organisation in living: organisms are: Cell, tissue, organ, system

(ii)A cell is a basic structural and function unit of life; it is bounded by a membrane containing nucleus and cytoplasm. Some cells are capable of independent existence, carrying out all the characteristics or life processes in living things. They may have processes like pseudopodia, cilia, flagella, etc. Cells also have inclusions, referred to as organales.

A tissue is a collection of cells which are similar in structure and perform similar functions. Some tissues cannot exist on their own but some can live on their own, e.a., Hydra. They have the same origin and occupy the same position in the body of the organism.

An organis a collection of different tissues that perform a common function or functions. Some organs carry out a single function. e.g., heart while others carry our more than one function, e.g., kidney.

A system; is made up of different organs that perform a particular function. Systems are peculiar to higher organisms.