Respuesta :
Answer:
Presence of Y chromosomes in approximately half the sperm.
Explanation:
Mature sperm cell consists of the following parts :
A head
A neck
A middle piece and
A tail.
Plasma membrane surrounds the complete body of sperm cell. Sperm head contains very little cytoplasm, an elongated haploid nucleus, the anterior portion of which is covered by a cap like structure called acrosome. The acrosome contains enzyme which help in the process of fertilization with ovum. Acrosome is derived from golgi apparatus. There is a short neck region which contains both the proximal and distal centriole. Proximal centriole plays an vital role in the first cleavage of zygote formed. Distal centriole gives rise to the the axial filament present in the long tail of sperm cell. The middle piece contains the mitochondria which are arranged spirally and produce energy for the movement of tail. The tail contains the central axial filament, small amount of cytoplasm and is surrounded by cell membrane as external sheath. The sperms cell swims at the rate of 1.5 to 3 mm per minute and reach the fertilization site within 30 minutes.
