Methotrexate inhibits the synthesis of DNA, RNA, and protein synthesis of the cells in the experiment.
Explanation:
Methotrexate competitively inhibits the enzyme dihydrofolate reductase (DHFR) which is involved in the synthesis of tetrahydrofolate from the inactive dihydrofolate. The methotrexate blocks the enzyme by binding to its active site thereby preventing further reaction of the dihydrofolate reductase enzyme and dihydrofolate. Tetrahydrofolate is a useful material for the de novo synthesis of thymidine, a nucleoside. And without thymidine, DNA synthesis is hindered. Methotrexate therefore inhibits the synthesis of DNA, RNA, thymidylates and of course protein synthesis.
Homeotic genes regulate the development of structures. Logically, then, the mutation of this gene must result in improper structure development, such as structures in abnormal places. The answer is C.
