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

Mouse sperm need a molecular VIP pass to reach the egg membrane

In most animals and plants, the life cycle of an individual begins with fertilization, when egg and sperm fuse to combine their genetic material. Together, they form the zygote, the first cell of an embryo that will eventually ...

Female skinks store sperm for dry spells

Female tree skinks can reproduce even when they have not encountered a male for more than a year, by storing sperm from previous mates, according to new research.

Coral cryopreservation for breeding key to survival

Flash-frozen sperm collected from corals in Florida and Puerto Rico was used to fertilize coral eggs from hundreds of miles away in Curaçao. The juvenile corals raised from this trans-Caribbean coupling demonstrate the reproductive ...

Molecule regulating sperm motility discovered

About 120 million unintended pregnancies occurred each year between 2015 and 2019 worldwide. While there are oral contraceptives for women, the development of oral contraceptives for men has not been successful. Now, a team ...

Scientists mail freeze-dried mouse sperm on a postcard

Scientists no longer have to worry about their bottles of mouse sperm breaking in transit. Researchers in Japan have developed a way to freeze dry sperm on a plastic sheet in weighing paper so that samples can withstand being ...

Testis-specific gene involved in sex ratio regulation discovered

Although enormous progress has been made over the past few decades in genetics, molecular biology and biochemistry, the ways in which living beings orchestrate their internal processes at the microscopic scale is still full ...

Chromosome positioning during sperm differentiation described

Chromosomes occupy specific regions of the cell nucleus called chromosome territories. In somatic cells, scientists have observed that there is a correlation between this positioning and genome regulation. In fact, alterations ...

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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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