Organisms and Their Environment

The distribution of organisms on Earth depends on climate and local habitat conditions. Variations in temperature and rainfall across regions lead to the formation of different biomes such as desert, grassland, rainforest, and tundra. Within each biome, organisms show specific adaptations that help them tolerate environmental stress.

Ecological Hierarchy:

Organism → Population → Community → Biome → Biosphere

Abiotic factors are the non-living components of the environment that strongly influence the survival and distribution of organisms.

Biotic factors include the effects of living organisms on one another. These include competition, predation, parasitism, mutualism, and commensalism.

Adaptations help organisms face environmental challenges efficiently. These may be structural, physiological, or behavioural.

Types of Adaptations:

Not all organisms can maintain a constant internal environment under changing external conditions. Organisms show different responses to survive stress such as extreme heat, cold, or dryness.

Climate is one of the strongest factors controlling biome formation. Long-term patterns of temperature and precipitation create broad biological regions with characteristic vegetation and animal life.

Distribution of major Biomes with respect to annual temperature and precipitation

An ecological niche refers to the functional role of an organism in its habitat, including how it uses resources, where it lives, and how it interacts with other organisms. Habitat tells where an organism lives, while niche explains how it lives in that place.

Quick Difference:

• Habitat = address
• Niche = profession or role

• Climate variations, specifically temperature and rainfall, determine the distribution of Earth's major biomes.
• An organism's survival depends on both abiotic factors (such as temperature and water) and biotic interactions (such as competition and mutualism).
• Organisms develop specific structural, physiological, or behavioural adaptations to overcome environmental challenges.
• To manage environmental stress, organisms can either regulate internal conditions, conform to the environment, migrate, or suspend their activities.
• A habitat is the physical address where a species lives, whereas an ecological niche is its functional role within that environment.