Primary sex determination- Concerns the determination of the gonads. In
mammals, determination strictly chromosomal; not influenced by the
environment. Most cases- female = XX; male= XY
Every individual organism has atleast one X Chromosome. Since the female has
2 X chromosomes, each of her eggs posses one X chromosome. The male posses an
X and a Y, so therefore the male can produce 2 kinds of sperm, one with an X
chromosome and one with a Y chromosome. If an offspring receives an X and a Y, then it
TheY chromosome carries a gene that encodes a testis determining factor. If a
person had an innumerable number of x chromosomes and one y chromosome, they
would be male. If a person is born with only a single x chromosome and no
second x or y, then they develop as a female, but are infertile.(not able to
More Primary Sex Determination- In the is absence of the Y chromosome , the primordial
gonad body develops into ovaries. the ovary then produces the estrogenic hormones,
which contains estrogen and other such hormones, enabling the development of the
Mullerian duct into the uterus, fallopian tubes, and upper end of the vagina.
In the presence of Y chromosome, the testes form. The testes secrete two major
enzymes. The first hormone, AMH(anti-Mulllerian duct hormone), destroys to Mullerian
duct. The second, testosterone, stimulates the masculinization of the fetus. During this
process the penis, scrotum, and other male anatomical structures form. The development
of the primordial breast is inhibited. The body, therefore, has the female phenotype unless
it is altered by two hormones created in the fetal testes.
The development of gonads is the only fetal organ development process that has
the chance of developing into more than one organ (under normal circumstances and
barring mutations). The primordial gonad ca
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