Which statements are true about steroids?

• A. I, II
• B. I, III
• C. I, II, III
• D. I, II, IV

Answer: (C)

Steroids are lipid molecules derived from cholesterol. Because they are fat-soluble, they readily cross cell membranes and travel in the bloodstream mainly bound to carrier proteins. Inside a target cell, they bind to intracellular receptors (in the cytoplasm or nucleus). The receptor–steroid complex then acts as a transcription factor, turning on or off specific genes and altering protein production. This genomic mechanism leads to slower onset but longer-lasting effects, such as changes in metabolic enzymes or hormone receptors in tissues.

So the statements that reflect these properties—being lipid-soluble and membrane-crossing, and acting through intracellular receptors to regulate gene expression—are the true ones. A statement claiming rapid, membrane-initiated signaling as the primary mode for classic steroids would not fit the typical mechanism, which is why the three statements that describe the genomic, receptor-mediated action are correct.