Navigation Links
Sperm


Schematic diagram of a sperm cell, showing the (1) acrosome, (2) cell membrane, (3) nucleus, (4) mitochondria, and (5) flagellum (tail)

A sperm cell, or spermatozoon (pl. spermatozoa) (in Greek: sperm = semen and zoon = alive), is the haploid cell that is the male gamete. It is carried in fluid called semen, and is capable of fertilising an egg cell to form a zygote. A zygote can grow into a new organism, such as a human. Sperm cells contain half of the genetic information needed to create life. Generally, the sex of the offspring is determined by the sperm, through the chromosomal pair "XX" (for a female) or "XY" (for a male). Sperm cells were first observed by Antoni van Leeuwenhoek in 1679.

Contents

Sperm structure and size

Individual spermatozoa are highly differentiated cells, composed normally of a head, basal body (or midpiece), and tail. The head contains some cytoplasm and the nuclear material for fertilization. The basal body contains a large concentration of mitochondria that provide the energy for sperm motility through the production of ATP. The spermatozoan tail is typically a flagellum used for propulsion.

In humans, sperm cells consists of a head 5 m by 3 m and a tail 50 m long. The tail flagellates, which we now know propels the sperm cell by rotating like a rutter not side to side like a whip. The cell is characterized by a minimum of cytoplasm.

Sperm production

Main article: Spermatogenesis

Sperm are produced in the seminiferous tubules of the testes in a process called spermatogenesis. Round cells called spermatogonia divide and differentiate eventually to become sperm. During sexual intercourse the sperm is deposited in the vagina - and then it moves to the ovum inside the ovary.

See also

External link


'"/>


(Date:2/16/2017)... Feb. 16, 2017  Genos, a community for ... it has received Laboratory Accreditation from the College ... presented to laboratories that meet stringent requirements around ... rigorous processes. "Genos is committed to ... practices. We,re honored to be receiving CAP accreditation," ...
(Date:2/10/2017)... Research and Markets has announced ... - Scientific and Commercial Aspects" to their offering. ... Biomarkers ... with therapy for selection of treatment as well for monitoring ... of disease in modern medicine. Biochip/microarray technologies and next generation ...
(Date:2/8/2017)... YORK , Feb. 7, 2017 Report Highlights ... The ... should reach $11.4 billion by 2021, growing at a compound ... Includes - An overview of the global markets for synthetic ... 2015, estimates for 2016, and projections of compound annual growth ...
Breaking Biology News(10 mins):
Other biology definition