Question

Which is false about the viability of mammalian sperms?

A. Sperm is viable for only 24 hours.

B. Sperm viability is determined by its motility.

C. Sperms must be concentrated in thick suspension.

D. It depends upon the pH of the medium as sperm is more active in the alkaline medium.

Answer 1

Hint: Sperm is the male reproductive cell or gamete, in oogamous type of sexual reproduction. Structure of the sperm represents a head, a middle piece and a tail. The head contains a haploid nucleus. The middle piece possesses numerous mitochondria which produce energy for the moment of tail or sperm.

Complete Answer:

- Sperm viability is the capacity of being alive, developing, or reproducing. 

- In this type of sexual reproduction, fusion between one large non motile static female gamete and a smaller motile male gamete takes place.

- Sperm cells are carried out of the male body in a fluid known as a semen. Humans Sperm or Mammalian Sperm can survive within the female reproductive tract for more than 5 days post coitus and also remains viable for several days. Therefore option A is wrong in the context of sperm viability.

- The human male ejaculates about 200 to 300 million sperm during a coitus under normal conditions.

- They should be at least 60 percent of sperms which must have normal shape and size and at least 40 percent of them must show vigorous motility.

- The interior portion of the head is covered by a cap-like structure acrosome. The acrosome is filled with enzymes that help fertilization of the ovum.

Sperm diagram is shown below.

So the correct answer is (A).

Note: Sperms are released from the seminiferous tubules. And then the sperm are transported to accessory ducts. Secretion from epididymis, seminal vesicle and prostate are essential for maturation and motility of sperms. The seminal plasma along with the sperms constitutes the semen.