(a) Write short notes on each of the following: (i) ecosystem; (ii) population; (iii) ecological succession in plants.
(b) List five ways by which nitrogen can be made available to the soil for plant growth.
(b) List five ways by which nitrogen can be made available to the soil for plant growth.
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
Correct Answer: Option n
Explanation:
(a)(i) Ecosystem: -
This is a self-supporting unit/ system.
it consists of all living organisms and the non-living factors, that interact with each other/are interdependent.
Each component influences the properties of the others.
The living organisms make up the biotic components, e.g. plants and animals
The non-living factors make up the abiotic components; e.g. soil/edaphic factors/climatic factors.
(ii) Population: This refers to the total number of organisms/individuals of the same kinds/ species living together within a habitat/area at a particular time. The size of the population varies due to different factors; e.g. natality/mortality/immigration/emigration.
(iii) Ecological succession in plants: - This is the orderly series of changes occurring in plant communities over a given period of time, until a stable/climax community is established. It usually commences in a newly formed open/barren habitat/abandoned farmland, which is usually as a result of human activities/natural disasters/ catastrophes. The pioneer/primary colonizers have short life cycles/span, which get replaced by other plants which thus derive nutrients from their remains. These latter secondary colonizers have longer life cycles/span. - The initial pace of a succession is rapid but it gradually slows down until a final/stable/climax community is reached
(b) Ways by which Nitrogen is made available to soil include:
(1) Through nitrogen fixation
(2) Through thunder storms and lightening
(3) By putrefaction/decay of organic matter
(4) By nitrification
(5) By application of artificial fertilizers
(6) By application of farmyard manure/organic fertilizers/poultry, droppings/animal dungs/green manure.
(a)(i) Ecosystem: -
This is a self-supporting unit/ system.
it consists of all living organisms and the non-living factors, that interact with each other/are interdependent.
Each component influences the properties of the others.
The living organisms make up the biotic components, e.g. plants and animals
The non-living factors make up the abiotic components; e.g. soil/edaphic factors/climatic factors.
(ii) Population: This refers to the total number of organisms/individuals of the same kinds/ species living together within a habitat/area at a particular time. The size of the population varies due to different factors; e.g. natality/mortality/immigration/emigration.
(iii) Ecological succession in plants: - This is the orderly series of changes occurring in plant communities over a given period of time, until a stable/climax community is established. It usually commences in a newly formed open/barren habitat/abandoned farmland, which is usually as a result of human activities/natural disasters/ catastrophes. The pioneer/primary colonizers have short life cycles/span, which get replaced by other plants which thus derive nutrients from their remains. These latter secondary colonizers have longer life cycles/span. - The initial pace of a succession is rapid but it gradually slows down until a final/stable/climax community is reached
(b) Ways by which Nitrogen is made available to soil include:
(1) Through nitrogen fixation
(2) Through thunder storms and lightening
(3) By putrefaction/decay of organic matter
(4) By nitrification
(5) By application of artificial fertilizers
(6) By application of farmyard manure/organic fertilizers/poultry, droppings/animal dungs/green manure.