human sperm is ____ like stucture
Answers
Answer:
A human sperm has distinct structure.
Answer:
Explanation:
Structure of Human Sperm:
The male gamete is called as spermatozoon or sperm. It is a single cell structure and it bears a haploid set of chromosomes in the nucleus.
Human sperm has a head, neck, midpiece and tail.
Head:
It is the anterior part of the sperm. Its shape varies from species to species.
The anterior most part of the head is occupied by the acrosome.
The acrosome is formed by the Golgi-body and it is bounded by a unit membrane.
It is full of sperm lysins and it helps in fertilization.
There is a nucleus just behind the acrosome which is slightly elongated and its posterior end has a notch.
The nucleus has a haploid set of chromosomes which have protamine's in addition to DNA.
The sperms of some species have a vacuole-like structure between the acrosome and nucleus which is called as a perforator.
The posterior notch of the nucleus harbors a proximal centriole which is to be contributed to the egg at the time of fertilization.
It helps at the beginning of the first cleavage.
Neck:
It is a small part which connects the head to the mid-piece.
It bears a distal centriole which remains at 90° to the proximal centriole.
The distal centriole gives rise to an axial filament which extends throughout the length of the mid-piece & tail.
It exhibits a fibrillar arrangement of 9 (doublet) + 2 (singlet).
Middle piece:
In the middle piece, the axial filament is surrounded by a sheath called manchette.
The manchette is made up of nebenkern (fused mitochondria) and little condensed cytoplasm.
In the sperms of some species, the posterior end of the middle piece may have a ring centriole. Its role is not clear.
Tail:
In the tail, the axial filament is covered by a sheath which is made up of 9 (singlet) fibers.
This the sheath is absent around the terminal end of the tail.
The whole sperm is bounded by a plasmalemma.
Most of the sperms are mono-flagellated.
.
.
i hope u understand
mark me brainiest !!!!
