Biomes are large regions of Earth that have similar or common vegetation and climatic conditions. They play a crucial role in sustaining life on Earth. They are defined by their soil, climate, flora, and fauna. Biomes have distinct biological communities that have been formed in response to a Shared physio-chemical climate.

In some aquatic environments, an inverse relationship between water temperature and fish meristic characters is observed - lower the temperature, more the vertebrae

Temperature, light, water, soil, humidity and altitude, etc.

This is the ecological interaction in which an individual species harm another without obtaining benefit, large powerful animals harm weak animals. Eg. animals destroyed at the feet of elephants.

The maximum number of organism that a region can support without environmental degradation is called carrying capacity.

Warm blooded animals, living in colder climates, tend to have shorter limbs, ears and other appendages when compared to the members of the same species in warmer climates.

Birds and mammals attain greater body size in colder regions than warmer regions (Bergmann's rule).

Stenohaline Animals	Euryhaline Animals
The animals which show tolerance only to a narrow range of salinities.	The animals which, can tolerate a wide range of salinities
Their distributional range is limited.	Their distribution shows a wide range

1. The characteristic of soil that determines the movement of water through pore spaces is known as soil permeability.
2. Soil permeability is directly dependent on the pore size. Water holding capacity of the soil is inversely dependent on soil porosity.

This is the level of exposure of plants to environmental factors that leads to neither injury nor reduction in growth and yield of crops.

Soil formation is called pedogenesis soil is formed from rocks which are the parent materials of soil, by weathering and is called embryonic soil (So soil is an edaphic factor).

1. Animals are known to modify their response to environmental changes (stress) in reasonably short time of spans. This known as Acclimatisation.
2. This is observed when people who have moved from the plains to higher altitudes show enhanced RBC count within a few days of settling in their new habitat. This helps them cope with lower atmospheric oxygen and higher oxygen demand.

Ecological niche is a term for the position of a species within an ecosystem, describing both the range of conditions necessary for persistence of species, and is ecological role in the ecosystem.

The natural home (or) environment of an animal, plant or other organism or it can be considered as the address of an organism

Hibernation:
Spending the winter in an inactive dormant state to escape in time, is called hibernation. E.g: Bears and Frogs.
Aestivation:
Spending the dry, hot period in an inactive state to escape in time is called aestivation .E.g: Snails and Fish.