Science Education Form 2

1.1 Interdependence Among Living Organisms


A) Species, Population and Community


Species:-
1. A species is the lowest unit in the classification of living organisms.
2. The common names of familiar animals and plants often denote the species.
3. Animals and plants of the same species usually live together.
4. Members of the same species look alike and behave in the same way.
5. Members of the same species are able to reproduce among themselves.

Population:-
1. A population is a group of individual animals of plants of the same species living in a given area.
2. A population increases if the number of individuals added to it exceeds the number lost through                       migration or death and vice versa.
3.There are likely to be different populations of organisms living in the same environment.

Community:-
1. Several populations of organisms living in the same area form a community.
2. A community has populations of plants and animals.
3. Members in a community interact and are dependent on one another for their survival.
4. A change of population of one organism affects the other members in the community.

B) Habitats and Ecosystems


Habitat:-
1. A habitat is a natural place in which organisms live.
2. A habitat may be a pond, a river, a bush, a sea-shore or a paddy field.
3. An organism in any habitat has its part to play and is dependent on other organisms for its survival.
4. A habitat provides organisms living in it with:
   a) Food
   b) Water
   c) Air
   d) Suitable temperature
   e) Protection
5. Every organisms choosing its own habitat. (Snakes - bushes, Sparrows - trees, Tadpoles - ponds)

Ecosystem:-
1. An ecosystem is a system formed by the interaction of living organisms and their environment.
2. Therefore, an ecosystem consist of the physical and the biological factors.
3. The physical factors factors include:
  a) Air
  b) Water
  c) Soil
  d) Temperature
  e) Light
  f) Minerals
The biological factors are the plants and the animals.
4. There are different types of ecosystem
  a) Jungle
  b) Desert
  c) Tundra region
  d) Sea
  e) Paddy field
  f) River
5. An ecosystem can provide different habitats
  Example:
  A jungle provide different habitats such as:
  a) Tall trees
  b) Damp soil
  c) Thick bushes
  d) Ponds
  e) Swamps
  f) Rocks