Question

Protozoans are actually
A)Cellular
B)Acellular
C)Unicellular
D)Multicellular

Answer 1

Hint: The Protozoa occupy a separate kingdom. Protozoans are the primitive eukaryotes which are found either as free-living or as parasites. They feed on organic matter like microorganisms or tissues and debris. Amoeba, Paramecium are few examples of protozoans.

Complete answer:
The protozoa are bigger than bacteria and contain a definite nucleus and other membrane bound organelles. They are unicellular eukaryotes so it is more like plants and animals. The main feature of protozoa is they can move and eat other small microorganisms.
Some characteristic features of Protozoa are:
1)They love to live in a moist environment.
2)They are unicellular eukaryotes and have heterotrophic mode of nutrition.
3)They have cilia or pseudopodia for locomotion.
4)Alternating generation takes place in protozoa.
Acellular means cell- free. An example of an acellular organism is the virus. It is a transition between living and non-living organisms.

Multicellular- The organisms having many cells are called multicellular. Example plants, animals.

Cellular organism- the organism which consists of either multicellular or unicellular.

Hence, the correct answer is option (C)

Note: The ecological significance of Protozoa are:
1)It is an important source of food for invertebrates.
2)They act as predators and eat algae, bacteria.
3)The protozoa help in controlling the number of bacteria.
4)Several species of protozoa are responsible for causing diseases in human beings like 5)Plasmodium causes malaria, Amoeba causes amoebic dysentery. Trypanosoma, Leishmania are also certain pathogenic species which cause diseases.