Related topics: eggs · fertilizer · genes · infertility · females

Researchers reveal why heat stress damages sperm

University of Oregon biologists have used the model organism Caenorhabditis elegans to identify molecular mechanisms that produce DNA damage in sperm and contribute to male infertility following exposure to heat.

Evolution of the Y chromosome in great apes deciphered

New analysis of the DNA sequence of the male-specific Y chromosomes from all living species of the great ape family helps to clarify our understanding of how this enigmatic chromosome evolved. A clearer picture of the evolution ...

Human white blood cells use molecular paddles to swim

Human white blood cells, known as leukocytes, swim using a newly described mechanism called molecular paddling, researchers report in the September 15th issue of Biophysical Journal. This microswimming mechanism could explain ...

Surprising coral spawning features revealed

When stony corals have their renowned mass spawning events, in sync with the moon's cycle, colonies simultaneously release an underwater 'cloud' of sperm and eggs for fertilization. But how do the sperm and eggs survive several ...

page 1 from 50

Sperm

The term sperm is derived from the Greek word (σπέρμα) sperma (meaning "seed") and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. A uniflagellar sperm cell that is motile is referred to as a spermatozoon, whereas a non-motile sperm cell is referred to as a spermatium. Sperm cells cannot divide and have a limited life span, but after fusion with egg cells during fertilization, a totipotent zygote is formed with the potential to develop into a new organism.

The spermatozoa of animals are produced through spermatogenesis inside the male gonads (testicles) via meiotic division. They are carried out of the male body in a fluid known as semen. Mammalian sperm cells can live for up to 3 days inside the female reproductive system.[citation needed]

Sperm cells in algal and many plant gametophytes are produced in male gametangia (antheridia) via mitotic division. In flowering plants, sperm nuclei are produced inside pollen.

This text uses material from Wikipedia, licensed under CC BY-SA