Question

Cells of leydig occur in
A)Testis of frog
B)Kidney of frog
C)Kidney of man
D)Testis of man

Answer 1

Leydig cells are also called interstitial cells present adjacent to the seminiferous tubules.

Complete answer:
Under the control of the pituitary Luteinizing hormone (LH) and in response to the gonadotropin releasing hormone (GnRH), Leydig cells produce testosterone in the testes. They are responsible for the biosynthesis and secretion of androgen which facilitates the development of reproductive tract in men and their reproductive functions too. They also help in maintaining spermatogenesis and extratesticular anabolic functions. LC occurs in fetal life. Masculinization is also directed by LC. Fetal Leydig cells produce the high levels of androgen (testosterone or androstenedione) required for differentiation of male genitalia and brain masculinization. Androgen production declines with loss of these cells, reaching almost a halt at postpartum. Testosterone then gradually increases to high levels with adult Leydig cell development from stem cells.
In frogs, both the gonads are attached to the kidneys. The Bidder's canal serves as the sperm receiving duct and passes through the kidney. They don't have separate sacs for holding the testis or the male reproductive organ. Humans have a specialised sac called scrotum that bears the tetis in them.
Humans have specialised cells in the kidney called the juxtaglomerular cells that are surrounded by blood vessels (different and afferent arterioles form meshwork of blood vessels all over the nephron).

Hence the correct answer is (D.) Testis of man.

Note: Leydig cells are also found in women's ovary and very rarely might lead to cancer.