Question

Which genus of bacteria does NOT have a cell wall?

• A. {Lactobacillus}
• B. {Staphylococcus}
• C. {Mycoplasma}
• D. {Escherichia}

Hint:

{Mycoplasma} bacteria are unique for their lack of a cell wall, making them resistant to antibiotics like penicillin, which target cell wall synthesis.

Answer 1

The Correct Option is C

The genus Mycoplasma is unique among bacteria because it does not have a cell wall. Most bacteria have a cell wall made of peptidoglycan, which helps protect the cell and maintain its shape. However, Mycoplasma lacks this structure, which makes it distinct from many other bacteria. The absence of a cell wall also makes Mycoplasma resistant to antibiotics that target cell wall synthesis, such as penicillin. These bacteria are typically smaller and more flexible, allowing them to take on various shapes (pleomorphism). Mycoplasma species are often pathogenic, causing diseases such as pneumonia and urinary tract infections.
In contrast, other bacterial genera like Lactobacillus (option A), Staphylococcus (option B), and Escherichia (option D) all have cell walls made of peptidoglycan, which is essential for their structural integrity and defense against environmental stresses. Thus, the correct answer is (C) Mycoplasma.