testes determining factor
a protein coded for by a gene on the short arm of the Y chromosome; a related TDF sequence is located on the X chromosome
Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row ...
The Testes and their Coverings (Figs. 1143, 1144, 1145)"The testes are two glandular organs, which secrete the semen; they are suspended in the scrotum by the spermatic cords.
Testes are suspended outside the abdominal cavity by the scrotum, a pouch of skin that keeps the testes close or far from the body at an optimal temperature for sperm development.
testes
2-5%[1]
Approximately 200- to 500-million spermatozoa (also called sperm or spermatozoans), produced in the testes, are released per ejaculation.
(plural: testes) [ L. testis - a witness, testicle]. The male gonad; where mature spermatozoa develop within the seminiferous tubules (mammals) or sperm lobes (insects) . Synonym: testicle.
In males the testes secrete the major androgen, testosterone. Synthesis of this hormone increases significantly at puberty, when it is responsible for adult sexual development.
testis (plural, testes)
The male reproducitve organ, or gonad, in which sperm and reproductive hormones are produced.
testis pl. testes
[Gk. testicle]
The male reproductive organ, or gonad, in which sperm and reproductive hormones are produced.
testosterone ...
Teratoma Tertiary structure, of protein Tesla Test cross[monohybrid] [dihybrid] Testes, human Testosterone TetanusSustained maximal contraction of a muscle.
There are 46,XY individuals who have testes make male hormones but fail to make androgen receptors (this gene is on the X chromosome). Due to the lack of androgen receptors the individual never forms male internal or external genitalia.
Around 200 million to 500 million spermatozoa (or 'sperm', for short), produced in the testes, are released per ejaculation. However, they make up only about 2-5% of the volume of semen.
In sequencing >600 clones from a human testes cDNA library, Michael Jones (Cambridge University) found that 3% were identical to known genes and 70% novel.
Spermatogenesis is the process of forming sperm cells by meiosis (in animals, by mitosis in plants) in specialized organs known as gonads (in males these are termed testes). After division the cells undergo differentiation to become sperm cells.
scrotum The pouch that contains the testes in most mammals.
scrub typhus Rickettsial disease transmitted by certain chigger mites.
scuba (self-contained underwater breathing apparatus) The use of tanks of compressed air for breathing underwater.
Spermatogenesis occurs in seminiferous tubules in testes.
The cell that undergoes meiosis is a primary spermatocyte.
Androgens A class of steroid hormones, exemplified by testosterone, that are responsible for the development of male secondary sexual characteristics; synthesized by the testes.
Angstrom (Ĺ) A unit of length equal to 10-10 meter.
Epididymis coiled tubules‚ found within the scrotum‚ that store sperm and are the site of their final maturation
(epi = upon‚ over; didym = testes) ...
 See also: Human, Organ, Cells, Trans, Sperm
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