(a)(1) Explain briefly chemosynthesis as a mode of nutrition.
(ii) Give two examples of organism that carry out chemosynthesis.

(b) List three gases in the atmosphere with their percentage composition. 

Gases in the atmosphere	Percentage composition

(c) (i) State four characteristics of a salt marsh habitat.
(ii) Explain briefly how plants are modified for anchorage in a salt marsh habitat.

(d) (i) List four bacterial disease associated with poor food hygiene.
(ii) State three effects of poor food hygiene.

(e) A person was involved in a car accident and became unconscious due to excessive blood loss. Explain briefly how the blood lost could be restored. 

(f) State three differences between tillage and bush burning as farming practices. 

Tillage	Bush burning