(a) Explain four reasons for which temperature decreases with height within the troposphere.
(b) With the aid of a diagram, describe the mode of formation of orographic rainfall.

(a) What is volcanic intrusion ?
(b) Describe the characteristics and mode of formation of a block mountain.
(c) List three landforms that are associated with intrusive volcanic activities.

(a) List: (i) three factors that influence weathering; (ii) two effects of landslides.
(b) Describe the following processes of weathering: (i) exfoliation; (ii) frost action.

(a) Define the term ecosystem.
(b) Describe the main components of the ecosystem citing two examples of each.
(c) Explain two ways in which the components of the ecosystem are interdependent.

The following are advantages of overpopulation except