Secretion of the androgen by Leydig cells of testis is under the regulatory influence of

Deficiency of which vitamin leads to the degeneration of the testes?

Which hormone produces an anabolic effect on protein and carbohydrate metabolism?

Which of the following hormones is responsible for the development of secondary sexual characteristics such as hoarseness in voice,growth of beard,and mustaches in males?

What is the location and secretion of the $Leydig$ cells?

State the location of the testis. Mention the functions and name of the hormones produced by it.