sperm


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sperm

or

spermatozoon

(spûr'mətəzō`ən, –zō`ŏn), in biology, the male gamete (sex cell), corresponding to the female ovumovum
, in biology, specialized plant or animal sex cell, also called the egg, or egg cell. It is the female sex cell, or female gamete; the male gamete is the sperm. The study of the ovum is included in the science of embryology.
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 in organisms that reproduce sexually. In higher animals the sperm is produced in the testis of the male; it is much smaller than the ovum and consists primarily of a head, whose nucleus bears the hereditary material (see chromosomechromosome
, structural carrier of hereditary characteristics, found in the nucleus of every cell and so named for its readiness to absorb dyes. The term chromosome
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) of the male parent, and a slender whiplike process (flagellum), which provides the motility necessary for fertilizationfertilization,
in biology, process in the reproduction of both plants and animals, involving the union of two unlike sex cells (gametes), the sperm and the ovum, followed by the joining of their nuclei.
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 in a fluid medium. In higher plants the sperm is contained in the pollenpollen,
minute grains, usually yellow in color but occasionally white, brown, red, or purple, borne in the anther sac at the tip of the slender filament of the stamen of a flowering plant or in the male cone of a conifer.
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 grain and is conveyed to the ovum by the pollen tube; in some lower plants (e.g., mosses and ferns) the sperm is actively motile.

Sperm

 

in plants, a nonmotile male sexual cell, or gamete. In higher plants, sperms are nonmotile because they develop inside a pollen tube, which forms upon the germination of a pollen grain (microspore). Fertilization takes place after the pollen tube ruptures upon reaching the female sex organ—the archegonium in gymnosperms or the embryo sac in angiosperms. In gymnosperms a pair of sperms forms as a result of the division of the generative cell. One of the sperms participates in fertilization, and the other dies. Both sperms participate in the fertilization of angiosperms, one fertilizing the ovum, and the other the secondary nucleus of the embryo sac. The male gametes of pteridophytes, bryophytes, and some gymnosperms (including Cycadopsida and ginkgos) are called spermatozoids; they are flagellate and motile.

sperm

[spərm]
(histology)

sperm

1. another name for semen
2. a male reproductive cell; male gamete
References in periodicals archive ?
In the first experiment of the current study among different disulfide bonds reducing agents, the combination of Hep+2ME was more efficient in sperm head decondensation, 7 to 9 [mu]m, in vitro compared to other groups (Figure 2).
A dichotomous chamber consisting of two wells connected by a shallow chamber made from thick acrylic plastic blocks was utilized to examine sperm choice (Fig.
Chromatin integrity was evaluated with toluidine blue stain [26]; with this procedure, sperm with normal chromatin look light blue or green, whereas dark blue or violet sperm are considered as having damaged chromatin.
The procedure developed by the Japanese team carries the promise of greatly simplifying sex selection for either in vitro fertilization (where sperm and egg join in a lab dish) or artificial insemination (where sperm are implanted into the female reproductive tract).
The obstacle course that sperm face as they race to fertilise an egg has been recreated by scientists in a breakthrough that may improve IVF treatments in the future.
This phenomenon known as leukocytic reaction is not well understood, but researchers said that, after crossing the cervix, the sperm cells that enter the uterus are attacked by the immune system, killing majority of them.
DNA fragmentation index: Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) In Situ DNA nick end labelling (TUNEL) assay was performed with a slight modification of sperm suspension after density gradient separation as previously described (10).
These infertile men had failed previous fertility treatment (intracytoplasmic sperm injection or ICSI).
Against the background of declining sperm counts, stopping smoking is very important.
Nonetheless, there is an exception to the law on anonymous donation - that is, if a sperm donor will sign a document that says he will co-parent with the would-be-mother.