Other

Frozen sperm retains its viability in outer space conditions

Zillionaires like Amazon founder Jeff Bezos who see the 'colonisation' of space as an answer to the Earth's ever threatened resources will be reassured to learn that human sperm retains its complete viability within the different ...

Obstetrics & gynaecology

Only 21% of women who use their frozen eggs become mothers

As the trend for older motherhood continues, amid warnings from experts about the sharp decline in a woman's fertility in her mid-30s, more and more women are considering egg freezing as a form of "insurance" against age-related ...

Health

Poor semen quality in Switzerland

Over the last 50 years, a marked decrease in sperm count has been observed in the western world. But what about the situation in Switzerland? Up until now, no study had evaluated the reproductive health of Swiss young men. ...

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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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