What is the number of chromosomes in a human sperm cell?

In the process of grafting,what is the part of the plant that possesses the root system called?

List four categories of contraceptive methods. State in brief two advantages of adopting such preventive methods.

Can these two methods,regeneration and fragmentation,be equated to be the same? Answer with a reason.

Which sex hormone is produced by the testes in males?

$(a)$ Trace the path of sperms from where they are produced in the human body to the exterior.
$(b)$ Write the functions of secretions of the prostate gland and seminal vesicles in humans.