Cholesterol is synthesized by all animal cells and is mainly synthesized in the liver. cholesterol also serves as a precursor for several important biological compounds including all, except a. insulin b. vitamin d c. bite salts d. testosterone

The correct answer is A insulin

Explanation:

Cholesterol is a complex lipid which act as precursor for the synthesis of steroid compounds such as vitamin D a lipid soluble vitamin,testosterone a steroid hormone and bile salt helps in fat digestion.

     Insulin is a peptide hormone it is composed of amino acids linked with each other by peptide linkages .As a result insulin cannot be synthesized from cholesterol.

then that particular organisms become extinct.