Question 8
- Define ecosystem.
- Explain three ways in which the biotic and abiotic components of the ecosystem depend on each other.
- Highlight three benefits of the carbon cycle.
Observation
This question was fairly popular among the candidates and the performance of the candidates who attempted the question was above average.
Quite a good percentage of the candidates who answered the question were able to define the ecosystem as the relationship and interaction among the living and non-living things within an environment.
The ways in which the biotic and abiotic components of the ecosystem depend on each other include:
- Autotrophs utilize sunlight, water and carbon dioxide during photosynthesis to produce their food
- Carbon dioxide, water, sunlight and nitrogen provide nutrients and energy for the growth of plants
- The primary consumers feed on the food produced by autotrophs from organic components
- The various activities of man are carried out on the soil
- The oxygen and carbon dioxide components of air are made constant through photosynthesis and respiration by living organisms
- The decomposers break down the remains of other biotic components to form soils
- Raw materials in the form of water, gases, and inorganic materials vital to the survival of the biotic components come from the physical environment
- Plants depend on soil for support
- Plants depend on soil for humus
- Fish depends on water for survival
- Plants depend on soil for supply of water and minerals
- Soil depend on plants and animals for humus
- Soils depend on plants and animals for weathering of parent rocks
- Soil depends on plants for cover and shelter
- Some animals depend on soil for their food e.g. earth worm
The benefits of the carbon cycle are:
- Plants depend on carbon dioxide for photosynthesis
- Plants absorb carbon dioxide and releases oxygen
- Animals take in oxygen and releases carbon dioxide into the atmosphere
- Animals depend on plants directly or indirectly for their food produced during photosynthesis
- Carbon dioxide influences atmospheric temperature
- Carbon cycle provides Carbon dioxide which is an important gas in the atmosphere.