(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.
Explanation
(a)(i) Habitat
The natural dwelling place of an organism. OR A place/locality where an organism lives successfully
(ii) Role of a decomposer in an ecosystem
Decomposers are organism which bring about the decay of dead parts/whole of plants/animals; to produce manure/humus; they release nutrients in them into the soil; which are absorbed by roots of plants; and are used to build up new plant tissues; they thus help in nutrient recycling; also release offensive gases/odour which pollute the air.
(b) Energy flow in a freshwater habitat;
Common aquatic plants/Pistia/Spirogyra/any correctly named aquatic plant; using energy from the sun; photosynthesize/produce food; the food is eaten by primary consumers/animals; small aqautic animals would be eaten by bigger aquatic animals/secondary consumers; tertiary consumer/a much bigger fish/any correctly named fish will feed on secondary consumer, in the process of feeding energy flows from one trophic level to another; decreases progressively; dead animals/plants decompose; energy is lost.
(c)(i) Harmful effects of microorganisms to plants
- They cause diseases
- They can cause undesirable qualities in plants/plant product
- They cause spoilage
- Reduction in yield
(ii) Beneficial effects of micro organisms to humans
- Bacteria/decomposers help to decay/decompose dead organisms to release nutrients
- Bacteria is used in cleaning/mopping up oil spillage
- Used in the fermentation of foods/cocoa beans/garri/locust beans/kenkey production
- Used to make vinegar
- Used in making alcoholic beverages/wine/beer/spirit
- Used in making some antibiotics/penicillin
- Used in the manufacture of insulin
- Used in making cheese/yoghurt/bread/Single Cell Proteins
- Used in making flax/tanning of leather;