Step 1: Understanding Mycoplasma.
Mycoplasma are bacteria that lack a cell wall and are known for their resistance to antibiotics like penicillin, which target cell wall synthesis.
Step 2: Analyzing the options.
(A) Their cells are of definite shape: Incorrect — Mycoplasma cells are pleomorphic, meaning they lack a fixed shape.
(B) They are resistant to lysis by osmotic shock: Incorrect — Due to the lack of a cell wall, they are susceptible to osmotic shock.
(C) Their growth is not inhibited by penicillin: Correct — As Mycoplasma lack a cell wall, penicillin, which inhibits cell wall synthesis, does not affect their growth.
(D) They are nonpathogenic to humans: Incorrect — Some species of Mycoplasma are pathogenic and can cause diseases like pneumonia.
Step 3: Conclusion.
The correct answer is (C) Their growth is not inhibited by penicillin, as Mycoplasma lack a cell wall.
List I | List II | ||
|---|---|---|---|
| A | Clostridium butylicum | I | Ethanol |
| B | Saccharomyces cerevisiae | II | Streptokinase |
| C | Trichoderma polysporum | III | Butyric acid |
| D | Streptococcus sp. | IV | Cyclosporin-A |

Identify the taxa that constitute a paraphyletic group in the given phylogenetic tree.
The vector, shown in the figure, has promoter and RBS sequences in the 300 bp region between the restriction sites for enzymes X and Y. There are no other sites for X and Y in the vector. The promoter is directed towards the Y site. The insert containing only an ORF provides 3 fragments after digestion with both enzymes X and Y. The ORF is cloned in the correct orientation in the vector using the single restriction enzyme Y. The size of the largest fragment of the recombinant plasmid expressing the ORF upon digestion with enzyme X is ........... bp. (answer in integer) 