Question

Mycoplasma are different from other prokaryotes by

• A. Absence of cell wall
• B. Presence of chitin
• C. Presence of murein
• D. Presence of proteins in cell wall

Answer 1

The Correct Option is A

Mycoplasma are a distinctive group of bacteria that deviate from most prokaryotes because they lack a cell wall, an essential feature of many other bacterial species. This absence of a cell wall contributes to their unique characteristics and antibiotic resistance. 

Step 1: Understanding Mycoplasma Characteristics - Mycoplasma species are unique because they lack a cell wall, which makes them resistant to beta-lactam antibiotics like penicillin, which target cell wall synthesis. - Instead of a rigid cell wall, Mycoplasma have a flexible plasma membrane, reinforced with sterols that provide structural support. - These bacteria are the smallest known free-living organisms and can cause various diseases, including respiratory and urogenital infections. 

Step 2: Evaluating the Options - Option (A) - Correct: The defining feature of Mycoplasma is their lack of a cell wall, setting them apart from typical prokaryotes. - Option (B) - Incorrect: Chitin is a polymer found in the cell walls of fungi, not in Mycoplasma. - Option (C) - Incorrect: Murein (peptidoglycan) is a key component of most bacterial cell walls but is absent in Mycoplasma. - Option (D) - Incorrect: Mycoplasma do not have a cell wall and thus do not contain wall proteins. 

Step 3: Conclusion The absence of a cell wall is the key distinguishing feature of Mycoplasma, making option (A) the correct answer.