| Group I | Group II |
| Streptomycin | Inhibits beta-subunit of RNA polymerase |
| Cycloheximide | Inhibits peptidyl transferase activity of 505 subunit |
| Rifamycin | Inhibits peptidyl transferase activity of 605 subunit |
| Chloramphenicol | Inhibits binding of formyl methionine tRNA to ribosome |
To solve this matching question, we need to correctly associate each antibiotic in Group I with its corresponding mechanism of action in Group II.
All the matches checked lead us to the answer: P-4, Q-3, R-1, S-2.
The correct matching option is therefore P-4, Q-3, R-1, S-2. Each antibiotic's mechanism of action was determined based on its biological effect on specific bacterial or eukaryotic ribosomal subunits or enzymes involved in protein synthesis.
Correctly match the herbicide with its mode of development of resistance in plants.

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) 