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

Doing it to death: Suicidal sex in 'marsupial mice'

Imagine if you only had one shot at passing on your genes before you died. It happens more often in the natural world than you might expect: suicidal reproduction – where one or both sexes of a species die after a single ...

Giant kraken lair discovered

Long before whales, the oceans of Earth were roamed by a very different kind of air-breathing leviathan. Snaggle-toothed ichthyosaurs larger than school buses swam at the top of the Triassic Period ocean food chain, or so ...

Diet has rapid effects on sperm quality

Sperm are influenced by diet, and the effects arise rapidly. This is the conclusion of a study by researchers at Linköping University, in which healthy young men were fed a diet rich in sugar. The study, which has been published ...

Human eggs prefer some men's sperm over others, research shows

Human eggs use chemical signals to attract sperm. New research from Stockholm University and Manchester University NHS Foundation Trust shows that eggs use these chemical signals to choose sperm. Different women's eggs attract ...

Scientists use skin cells to create human sperm

Scientists in Spain on Wednesday they had created human sperm from skin cells, a medical feat which could eventually lead to a treatment for infertility.

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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.

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