NCERT Summary: The Living Organisms - Characteristics & Habitats | Science Class 6 PDF Download

What is Habitat?

• The surrounding where an organism lives, where it can find food, shelter and a favourable condition for breeding is known as its habitat.

Adaptations

• The ability of living organisms to adjust themselves to the surroundings is called as adaptation.
• Adaptations are the changes in structure or behaviour of an organism that will allow the organism to survive in that habitat.

Types of habitat

There are two types of habitat:

• Terrestrial habitat
• Aquatic habitat

1. Terrestrial habitat

• It refers to the land where all plants and animals survive.
• Animals and plants which live on land are called as terrestrial animals and terrestrial plants.
• Terrestrial habitat is further classified into:
  (i) Forests
  (ii) Grasslands
  (iii) Deserts
  (iv) Mountains
  (v) Polar Regions

(i) Forest

• These are large areas covered with trees and plants.
• Organisms living in the forest depend upon abiotic factors like air, availability of water, temperature, sunlight etc.
• Three types of forests are tropical forests, temperate forests and boreal forests.

(ii) Grasslands

• These are mainly covered by long and thick grasses.
• Temperature ranges between -20℃ and 30℃.
• Annual rainfall they receive varies between 50cm and 90cm.

(iii) Deserts

• These are the areas that receive scanty rainfall.
• These are dry with sand covering the whole region.
• Deserts are mostly hot regions but some of them are even too cold regions.

(iv) Mountains

• These regions are rocky and dry.
• Sometimes water occurs as flowing streams.
• Plants present on hills are xerophytes. These are conical and evergreen.

(v) Polar region

• These regions are covered with high snowy peaks.
• Animals found here are adapted by having thick furry coat on the skin.

Aquatic habitat

It refers to the region covered with water where plants and animals survive.

(a) Freshwater habitat: These are the water bodies filled with fresh water. These include rivers, lakes, ponds, streams etc.

(b) Marine habitat: Ocean and seas are termed to be marine habitat. These are full with life. Different varieties of organisms exist in marine habitat.

(c) Coastal habitat: This is the region represented by the place where land meets the sea.

Acclimatisation

• The ability of an organism to make small adjustments or changes in the body in a short period of time to adjust itself to the surrounding atmosphere is called acclimatisation.
• There are two types of components of a habitat:
  (i) Biotic components
  (ii) Abiotic components

Biotic components 

• It include all the livings organisms in a habitat, i.e. plants, animals and microorganisms.

Abiotic components 

• It includes all the non-living things in a habitat, i.e. air, soil, water, sunlight and temperature.
• The favourable conditions for survival of living organisms are provided by abiotic components.

Abiotic components

(i) Air

• Air is essential for all the living organisms on earth.
• Plants and animals take in oxygen from the air during respiration.
• Air is required by organisms to cool their body.

(ii) Soil

• Soil is the topmost layer of the earth.
• Soil is rich in minerals and microorganisms which help in different ways for plant growth.

(iii) Water

• Water forms a medium for many metabolic reactions taking place inside the body.

(iv) Sunlight

• Sun is the ultimate source of energy for all the living organisms on earth.
• Plants depend on sunlight for synthesising their food by the process of photosynthesis.

(v) Temperature

• Temperature at a place depends on the sunlight available at the particular place.
• Temperature also influences the humidity of that particular place.