NEET Practice Questions (MCQs) with Answers & Solutions

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment (such as air, water, and mineral soil), interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows.

A food chain represents the flow of energy from one organism to another through consumption. Multiple interconnected food chains form a food web, and each step or link in a food chain is known as a trophic level, which helps in understanding the energy flow.

Primary consumers are organisms that eat primary producers (such as plants). Pigeons that eat wheat are consuming plant material, making them primary consumers.

In a biotic community, primary consumers are organisms that directly consume producers (plants). These are typically herbivores or grazing animals. They play a crucial role in transferring energy from producers to higher trophic levels in the food chain.

Phosphorus is primarily stored in parental rock as phosphates, and nitrogen is mostly found in the environment, particularly in the atmosphere as nitrogen gas (N2). These elements are crucial for various biological processes and are cycled through ecosystems.

An ecosystem includes both biotic (living) components such as plants, animals, and microorganisms, and abiotic (non-living) components like soil, water, and air. The interaction between these components sustains the ecosystem.

Decomposers play a crucial role in breaking down dead organic matter, which recycles nutrients back into the ecosystem. Without decomposers, the flow of nutrients would stop, which would disrupt the ecosystem's functional efficiency.

The detritus food chain begins with dead organic matter and is decomposed by microorganisms such as bacteria. Hence, the correct option is 'Bacteria'.