(a)In an experiment on soil porosity, the following measurements were taken and recorded: Volume of dry soil = 50 cm³, Volume of water = 50 cm³, Total volume of soil and water = 75 cm³. Use the above information to (i) find the volume of air space in the soil sample. (ii) calculate the porosity of the soil sample. (b) Mention three reasons why soil porosity is important in agriculture. (c) State four characteristics of each of igneous and sedimentary rocks.

(a) Define the term weed (b) Describe four methods of weed control. (c) Give six reasons for controlling weeds on the farm.

(a) List five aims of crop improvement (b) Define the term selection in crop improvement. (c) List three methods of selection. (d) Explain the following genetic terms: (i) homozygotes (ii) back cross (iii) dominance.

(a) Give four reasons for rearing goats in West Africa. (b) List three advantages and three disadvantages of the extensive system of rearing goats in West African. (c) State six general characteristics of West African cattle breeds.

(a) State seven characteristic features of a good layer. (b) Describe the preparations to be carried out for receiving day old chicks for rearing. (b) Explain how poor storage facilities affect agricultural marketing.