Question

Which of the following is known as the structural and functional unit of the environment?
(a) Ecosystem
(b) Food web
(c) Food chain
(d) Producers

Answer 1

Hint: This term was first coined by A. G. Tansley, an English botanist, in 1935. They consist of a population of organisms together by their physical environment and interacting with each other. It together constitutes all the living and the non-living factors.

Complete answer:
The ecosystem is the structural and functional unit of ecology where the living being interconnects with one another and the neighboring environment.
An ecosystem is often classified into its abiotic constituents, comprising minerals, climate, soil, water, sunlight, and all other non-living elements, and its biotic constituents, comprising all its living members.
There are two types of ecosystems, which are terrestrial ecosystems and aquatic ecosystems. Terrestrial ecosystems are exclusively land-based ecosystems. Terrestrial ecosystems are often further grouped into broad categories called biomes, based largely on climate. Examples of terrestrial biomes include tropical rain forests, deserts, coniferous forests, deciduous forests, and tundra. Water supports various lives. Organisms that survive in water are described as aquatic organisms. They depend on water for their food, shelter, reproduction, and all other survival activities. These can be further divided into two types which are freshwater ecosystems (no salt content, eg- ponds, rivers) and marine ecosystems (salt content, eg- seas and oceans).

Additional information:
Biosphere: The biosphere is the zone of air, land, and water where organisms survive. It is basically referred to as the worldwide sum of every ecosystem and made up of various layers containing the atmosphere, the lithosphere, and the hydrosphere.
Food chain: The food chain is described as the distribution of the living organism in a population in which one organism consumes another organism.
Food Web: The food chains when interconnected together will form a food web. It comprises all the food chains within a single ecosystem called the food web.

So, the correct answer is 'Ecosystem'.

Note:
Ecosystems are often small, like the tide pools present near the rocky shores of the many oceans, or very massive, like the Amazon Rainforest in South America. Ocean ecosystems are most common on Earth, like oceans and the living organisms they comprise cover 75 percent of the Earth's surface. The ecosystems of freshwater are only around 1.8 percent of the total earth’s surface and are rarest.