How is the body of a sperm suited for fertilization of an egg?
1 Answer
Sperm is a highly modified live cell suited for reaching an egg and for subsequent fertilisation.
Explanation:
Sperm is having three distinct parts: head, middle piece and tail.
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Head has acrosomal cap: an organelle derived from Golgi bodies. Single membrane bound acrosome contains lytic enzyme hyaluronidase to dissolve hyaluronic acid, a glue like material which binds follicular cells around egg.
Acrosomal enzyme, released from large number of sperms which arrive near the egg, helps in opening a passage for a lucky sperm to make the first contact with egg.
Sperms reach an egg by swimming/flagellar action. Tail of the sperm is a flagella that originates from distal centriole of sperm. Distal centriole is present in the neck region. ( Proximal centriole enters the egg cytoplasm along with sperm nucleus. ) Tail is the appendage for locomotion of sperm.
Sperm must also get a steady supply of energy from mitochondrial cloud present in the middle piece. Mitochondria does that by aerobic respiration.
As the sperm is a motile cell, cytoplasm along with various organelles are discarded during its structural modification from spermatid.