(a) (i) What is a habitat?
(ii) Explain briefly three roles of a decomposer in an ecosystem.
(b) Explain briefly energy flow in a freshwater habitat.
(c) (i) State three harmful effects or microorganisms to plants
(ii) State six beneficial effects of microorganism to humans.
(a) (i) Explain the term agglutination as used in blood transfusion.
(ii) The table below represents blood transfusion between blood donors and recipients.
| Donor | Recipient | ||||
| A | B | AB | O | ||
| A | |||||
| B | |||||
| AB | |||||
| O | + | ||||
(b) Explain how each of the following organisms are adapted for obtaining food.
(i) Mosquito larva
(ii) Dodder plant
(iii) Grasshopper
(a) State two difference between tactic and nastic movements in plants.
(b) Give two examples each of organisms that show:
(i) tactic movement
(ii) nastic movement
(c) (i) State three ways of caring for the mammalian skin.
(ii) List three stimuli to which the mammalian skin is sensitive.
(d) State five effects of high temperature on a terrestrial habitat.
(e) (i) What is courtship behaviour in animals?
(ii) List three courtship behaviours in animals.
(f) Name three organisms that carry out holozoic mode of nutrition.
(g) Explain briefly how fingerprinting can be used to detect crime.
(a) Explain briefly sexual reproduction in Rhizopus.
(b) A student suddenly stepped on a big snake, he cried for help and ran away.
(i) Name the hormone produced in the body for the reaction.
(ii) In which part of the human body is the hormone named in (b) (i) produced?
(iii) State five changes that must have taken place as a result of the hormone named in (a) (i).
(c) (i) In tabular form, state three differences between excretion in flowering plants and excretion in humans,
(ii) List two organelles found in plant cell that are responsible for the excretion of metabolic wastes.
(a) Explain how the leaf of a flowering plant is adapted for photosynthesis.
(b) Describe briefly the mode of feeding in tapeworm.
(c) Name one mineral element each needed for the proper functioning of :
(i) bones (ii) red blood cells
(iii) thyroid gland.
(d)(i) State three benefits of including roughages in the diet of humans.
(ii) State three reasons why proteins are important to humans.
