Hormones which interact with membrane-bound receptors normally do not enter the target cell but generate second messengers( cyclic AMP, IP

3

, etc) which in turn regulate cellular metabolism in figure a.

Hormones which interact with intracellular receptors (e.g. steroid hormones, iodothyronines etc.) mostly regulate gene expression or chromosome function by the interaction of hormone- receptor complex with the genome. cumulative biochemical actions result in physiological and developmental effects.

So, the correct answer is 'A-Generation of a second messenger, B- Biochemical responses, C- Physiological responses'.

Thus, the mechanism of action of steroid hormones is to modulate gene expression in target cells. By selectively affecting transcription from a battery of genes, the concentration of those respective proteins are altered, which clearly can change the phenotype of the cell.