OVERVIEW OF THE IMMUNE SYSTEM
IMMUNITY INNATE AND ADAPTIVE
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a bacteriophage
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a virus
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a protist
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bacteria
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Detailed explanation-1: -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.
Detailed explanation-2: -Unlike the eukaryotic (true) cells, bacteria do not have a membrane enclosed nucleus. The chromosome, a single, continuous strand of DNA, is localized, but not contained, in a region of the cell called the nucleoid. All the other cellular components are scattered throughout the cytoplasm.
Detailed explanation-3: -A prokaryotic cell is a simple, single-celled (unicellular) organism that lacks a nucleus, or any other membrane-bound organelle.
Detailed explanation-4: -The cell types in Bacteria and Archaea are considered as “prokaryotes.” The use of the term prokaryote was first introduced as a result of electron microscope studies showing a shared simple cell structure among bacteria (Stanier & Van Niel 1962).
Detailed explanation-5: -Bacteria lack a membrane-bound nucleus and other internal structures and are therefore ranked among the unicellular life-forms called prokaryotes.
Detailed explanation-6: -Prokaryotes are single-celled organisms belonging to the domains Bacteria and Archaea. Prokaryotic cells are much smaller than eukaryotic cells, have no nucleus, and lack organelles. All prokaryotic cells are encased by a cell wall. Many also have a capsule or slime layer made of polysaccharide.