A pharmaceutical company sets out to design a drug to inhibit the response of cells to testosterone, a steroid hormone. Which of the following is most likely to be the result of this drug? (A) a decrease in G protein activity (B) a decrease in transcriptional activity of certain genes (C) an increase in receptor tyrosine kinase activity (D) an increase in cytosolic calcium concentration

(B) a decrease in transcriptional activity of certain genes

Explanation:

Testosterone is a steroid hormone, for which receptors are present inside the cell as it can easily pass the lipid bilayer. Like other steroid hormones, testosterone shows its affects by modulating transcription of its responsive genes.

After binding with receptor, it makes a hormone-receptor complex that binds with promoters of its responsive genes. If a drug is inhibiting response of testosterone, it must be decreasing the transcriptional activity of some genes, which are modulated by testosterone.

Thus, the correct answer is option (b).