A team of bio-scientists affiliated with a host of institutions across the U.S. has developed a gene editing technique to produce newborn pigs immune to porcine reproductive and respiratory syndrome, also known as blue-ear ...
Researchers in Japan led by the RIKEN Center for Biosystems Dynamics Research, Kobe and Osaka Metropolitan University, Osaka, have discovered that whale shark vision has uniquely temperature-dependent adaptations unseen in ...
Researchers at Tel Aviv University have developed a hybrid micro-robot, the size of a single biological cell (about 10 microns across), that can be controlled and navigated using two different mechanisms—electric and magnetic. ...
Bio & Medicine
Mar 27, 2023
0
408
Scientists from Denmark and China have estimated germline mutation rates across vertebrates by sequencing and comparing genetic samples from 151 mother, father, and offspring trios from 68 species of mammals, fishes, birds ...
For decades, researchers and the public have been captivated by the deep-diving sperm whales, highly social animals who live in groups of mothers and calves. The whales communicate with Morse code-like series of clicks called ...
Plants & Animals
Sep 12, 2022
0
656
In a discovery that challenges over a century of evolutionary conventional wisdom, corals have been shown to pass somatic mutations—changes to the DNA sequence that occur in non-reproductive cells—to their offspring. ...
Evolution
Aug 31, 2022
0
302
The two-meter skull of a newly discovered species of giant ichthyosaur, the earliest known, is shedding new light on the marine reptiles' rapid growth into behemoths of the Dinosaurian oceans, and helping us better understand ...
Evolution
Dec 23, 2021
0
2592
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 ...
Other
Aug 5, 2021
4
422
A team of researchers from the University of Aveiro and the University of Porto, both in Portugal, and the University of Birmingham in the U.K. has found that for humans, the brain and testis have the highest number of common ...
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 ...
Evolution
Oct 6, 2020
4
1035
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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