IMMUNOLOGY

Detailed explanation-1: -Bacteria are single celled microbes that lack a nucleus. Archaea are like bacteria, but they have different structures and properties. This gives them the ability to live in extreme environmental conditions. Protozoa are unicellular microorganisms that have nuclei.

Detailed explanation-2: -Following are some of the examples of unicellular organisms: Escherichia coli. Diatoms. Protozoa.

Detailed explanation-3: -A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms.

Detailed explanation-4: -Bacteria lack a membrane-bound nucleus and other internal structures and are therefore ranked among the unicellular life-forms called prokaryotes.

Detailed explanation-5: -Prokaryotes are organisms whose cells lack a nucleus and other organelles. Prokaryotes are divided into two distinct groups: the bacteria and the archaea, which scientists believe have unique evolutionary lineages. Most prokaryotes are small, single-celled organisms that have a relatively simple structure.