Question

With the help of labelled diagram describe the structure of human sperm.

Answer 1

Sperm is the male gamete. It is a motile, microscopic, elongated cell. It is divisible into three parts: head, middle piece, and tail.

Head: The sperm head is oval in shape and contains a haploid nucleus. Above the nucleus, there is a cap-like structure called the acrosome. It is formed from the Golgi body. The acrosome contains hydrolytic enzymes, hyaluronidase, and proteolytic enzymes like zona lysins and corona penetrating enzymes.

Neck: It is a very short region having two centrioles, i.e., proximal centriole and distal centriole.

Middle piece: It has an axial filament surrounded by 10-14 spiral turns of mitochondria (nebenkern). It produces the energy necessary for the movement of sperm.

Tail: It is a long, slender, and tapering part containing cytoplasm and a fine thread- axial filament. The axial filament arises from the distal centriole and travels throughout the length of the tail. It is partly surrounded by the plasma membrane (main piece). The part without a plasma membrane is called the end piece.