Question

In an aquatic environment, microscopic animals and plants are collectively known as
A. Commensals
B. Herbivores
C. Flora and fauna
D. Planktons

Answer 1

Hint:-By water, aquatic environments bind humans, land and wildlife. Both marine environments are wetlands, waterways, streams, and coastal estuaries, essential components of the complex workings of the Planet and important to human economies and wellbeing.

Complete solution:
Nutrients, shelter, aid, or locomotion from the host species can be acquired by the commensal species that benefits from the association, which is unaffected. Sometimes, the commensal relationship is between a larger host and a smaller commensal. By the association, the host organism is largely unchanged, while the commensal species can exhibit great morphological adaptation. It is possible to equate this relationship with mutualism, in which all organisms benefit. The remora (family Echineidae) that roams attached to sharks and other fish is one of the best-known examples of a commensal.

A herbivore is an organism that feeds mainly on plants. From small insects such as aphids to massive, lumbering elephants, herbivores vary in scale. Herbivores also have physical traits that assist them to consume rough, fibrous plant matter. There are large molars in many herbivorous mammals. These big teeth allow them to chew leaves and turf.

Biologists invented the term flora and fauna to refer to a range of plants and animals specified in a given geographical area.

For all such species, including some algae , bacteria, protozoans, crustaceans, molluscs and coelenterates, as well as members of virtually any other phylum of mammals, the word plankton is a common designation. Plankton, aquatic and freshwater species, which live in a drifting state because they are nonmotile or too small or weak to swim toward the current.

So from these discussions we can conclude that Planktons are collectively referred to as microscopic animals and plants in aquatic environments. Therefore the correct answer is option (D).

Note:- Plankton provides both aquatic and freshwater environments with a productive basis , providing food for larger species and indirectly for humans whose fisheries rely on plankton. As a human resource, in spite of its high biological productivity and large scope, plankton has only begun to be produced and used. In multiple occasions, it has been seen that large-scale algae cultures are theoretically feasible.
As a source for food and for gas exchange, phytoplankton may become increasingly necessary in space travel. The carbon dioxide released by spacecraft workers during respiration would be converted by algae into organic compounds, while the oxygen released during this process would sustain human respiration.