The smallest living cells are

Question

Question

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Answer 1

Correct Answer: Mycoplasma

Rationale:

Mycoplasma are the smallest living cells known, with some species measuring as little as 0.2 to 0.3 micrometers in diameter. They lack a cell wall, which contributes to their small size and unique properties among prokaryotes.
Mycoplasma are capable of surviving without oxygen and can be found in a variety of environments, including as parasites in humans and animals.

Explanation of Other Options:

Bacteria

Rationale: Bacteria are larger than mycoplasma, typically ranging from 0.5 to 5 micrometers in size. They have a cell wall, which gives them a more defined shape and rigidity compared to mycoplasma.

Fungus

Rationale: Fungi are much larger organisms compared to mycoplasma and bacteria. They are eukaryotes, meaning they have a complex cellular structure with a nucleus and other organelles. Fungal cells can be single-celled (like yeasts) or multicellular (like molds and mushrooms).

Bacteriophage

Rationale: Bacteriophages are viruses that infect bacteria. They are not considered living cells as they cannot carry out metabolic processes on their own and require a host cell to replicate. They are much smaller than mycoplasma, typically measuring about 20-200 nanometers.

Conclusion:

Among the given options, mycoplasma are the smallest living cells. They are unique among prokaryotes due to their lack of a cell wall and their ability to thrive in a variety of environments. This distinctive feature sets them apart from other microorganisms such as bacteria, fungi, and viruses like bacteriophages.