Question

What is sperm?

Answer 1

Hint: The male reproductive cell which is also known as the male gamete is produced by the meiosis of the germ cells. They are haploid, microscopic cells that fuse with the female gamete (egg) to fertilize it and form the diploid zygote. They are formed in the testis and are transported to the urethra by the vas deferens or sperm duct.

Complete answer:
The process of formation of sperms is known as spermatogenesis that occurs in the seminiferous tubules of the testes of humans. The microscopic structure is divided into three parts:
1. Head- It contains the nucleus which holds the DNA. The acrosome cap covering the anterior portion contains several enzymes like hyaluronidase (acrosin) which dissolves the outer covering of the egg cell during fertilization.
2. Middle piece- It is an elongated structure that is packed with mitochondria. These mitochondria provide energy to the sperm for motility. The point that connected the middle piece and the head is known as the neck, which contains the centriole.
3. Tail- The longest portion of the sperm structure which is the percent of the length of the sperm. It helps in the movement of the sperm in the semen.

Semen is the nutritive fluid that nourishes the sperm and is used in the transport of collective secretions of the seminal vesicles, prostate gland, and urethral glands.

Note:
The germ cells divide to form sperms through meiosis, but the sperms cannot divide further. They have a limited lifespan. During normal coitus, a human male ejaculates a million sperms out of which the only one fertilizes the egg. The rest of the sperms die in the process after staying alive in the uterus for days.