Class 11 · Biological Classification

Mycoplasma: Cell Wall-Free Prokaryotes — NEET Biology

✅ Asked in NEET 2017
✅ NEET 2017 PYQ

Which among the following are the smallest living cells, known without a definite cell wall, pathogenic to plants as well as animals and can survive without oxygen? NEET 2017

QuestionNEET 2017

Which among the following are the smallest living cells, known without a definite cell wall, pathogenic to plants as well as animals and can survive without oxygen? NEET 2017

Answer & NCERT explanation

Correct answer: B Mycoplasma

Mycoplasma are the smallest living cells lacking a definite cell wall, making them pleomorphic. They are pathogenic to both plants and animals and can survive in anaerobic conditions. Pseudomonas has cell wall, Nostoc is cyanobacteria with cell wall, and Bacillus also has peptidoglycan cell wall.

Read more NCERT concept on the PYQ

📖 NCERT Source

The Mycoplasma are organisms that completely lack a cell wall. They are the smallest living cells known and can survive without oxygen. Many mycoplasma are pathogenic in animals and plants.

NCERT Biology · Class 11 · Chapter 2 · Paragraph 16
How NTA Uses This Concept

Mycoplasma are unique prokaryotes that completely lack a cell wall, making them the smallest living cells known. They are also anaerobic (can survive without oxygen), which sets them apart from most bacteria. Students commonly confuse Mycoplasma with other prokaryotes and forget that lack of a cell wall is their defining feature—this makes them susceptible to osmotic stress but allows them unusual flexibility. To answer correctly, remember: Mycoplasma = no cell wall + smallest size + pathogenic to animals/plants. NTA tests this because it challenges the standard

❓ Frequently Asked Questions
What does NCERT say about Mycoplasma are organisms that?
The Mycoplasma are organisms that completely lack a cell wall. They are the smallest living cells known and can survive without oxygen.
Has this concept appeared in NEET?
Yes — appeared in NEET 2017. Explicitly states Mycoplasma lack cell wall, are smallest living cells, survive without oxygen
Which chapter is this from?
Biological Classification, Class 11 NCERT Biology.

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