What are the functions of testis in the human male reproductive system?

What are the functions of testis in the human male reproductive system? Why are these located outside the abdominal cavity? Who is responsible for bringing about changes in appearance seen in boys at the time of puberty?

Answer:
Functions of testis:

  • Produce sperms
  • Produces male hormone/testosterone.

These are located outside the human body, as sperms need lower temperature than the normal body temperature to mature.
Testosterone is responsible for bringing changes at the time of puberty in boys.