Identify the ejaculatory duct from the given diagrammatic representation of the male reproductive system.

$A$: Failure of testes to descend into the scrotum causes sterility in man. $R$: Higher internal body temperature is not suitable for sperm development.

Which duct is formed by the union of the vasa efferentia and the seminiferous tubules?

Where are the $Leydig$ cells found?

$A$ pair of bulbourethral glands, also called $...A...$ glands, are present on either side of the $...B...$. They secrete $...C...$ fluid and $...D...$ for lubricating the penis. Here $A, B, C$, and $D$ are:

What is present in high concentration in the seminal plasma?