Give a long answer to the question given below:
 
Given below are some situations. Examine them and explain their possible effects on an individual:
Answer variants:
motility
increasing
infertility
urethra
decreased
fertility
ureter
semen
 
a. The testes of a male fail to descend into the scrotum during embryonic development.

The condition given is leading to
due to impaired sperm production and
temperature. 
 
b. The vas deferens in a man becomes blocked.
 
Sperm cannot reach the
, causing infertility due to azoospermia (absence of sperm in semen).
 
c. The prostate gland and seminal vesicles are non-functional.
 
The condition given reduces
volume and deprives sperm of nutrients and a medium for
, causing infertility.