NEET Zoology - MCQ Practice Questions

Decomposers are living organisms that break down dead matter, making them biotic components. Soil, water, and temperature are abiotic components.

Solar radiation captured by photosynthetic organisms is the primary energy source for almost all ecosystems on Earth.

The 10% law states that only about 10% of energy is transferred to the next trophic level; the remaining 90% is lost as heat and used in metabolism.

Primary succession occurs on bare, newly exposed surfaces with no pre-existing soil or organisms, such as volcanic islands.

Carrying capacity (K) is the maximum population size an environment can support with available resources without degradation.

CO₂ is the major anthropogenic greenhouse gas, comprising about 76% of total greenhouse gas emissions, contributing significantly to global warming.

Transpiration is the release of water vapor by plants through stomata in leaves. Evaporation refers to water bodies.

Disease transmission increases with population density, making it a density-dependent factor. Natural disasters are density-independent.

In a forest, one large tree (producer) supports many insects and parasites, creating an inverted pyramid of numbers.

Fungi are primary decomposers that break down dead organic matter. Earthworms are detritivores, not true decomposers.

CFCs from refrigerants and aerosols release chlorine atoms that catalytically destroy ozone molecules in the stratosphere.

Coal is a non-renewable fossil fuel formed over millions of years. Solar, wind, and geothermal are renewable resources.

Biodiversity hotspots are regions with high concentration of endemic species and exceptional species diversity, like Western Ghats in India.

The Western Ghats is one of the world's 34 biodiversity hotspots with over 7,400 species of plants, many endemic to the region.

Secondary succession occurs after disturbance to an existing ecosystem where soil remains intact, allowing faster recovery.

This law states that two species competing for identical resources in the same habitat cannot coexist; one will be outcompeted.

Mutualism benefits both organisms. Nitrogen-fixing bacteria receive carbohydrates from legumes while providing usable nitrogen.

Understanding ecological terms and their definitions

Step 1: Analyze each option

Step 2: Match the key phrase "varies in different environmental contexts"

The question emphasizes that a species' role CHANGES depending on conditions — this is the ability to adapt and shift function, not a fixed characteristic. This is plasticity/versatility.

Step 3: Example confirmation

A generalist species like a crow eats different foods in different habitats (urban vs. rural) — demonstrating ecological plasticity, not fixed niche breadth.

Answer: (D) Ecological plasticity or ecological versatility

Jim Corbett National Park (originally Hailey National Park) in Uttarakhand was India's first national park, established to protect tigers.

Biomagnification is the process where persistent pollutants like DDT accumulate in higher concentrations as you move up the food chain.