I need help in answering these questions with short descriptions:
1. Sex determination and sex differentiation in human.
2. Forms of interaction between allelic genes
3. Rhesus-negative man with I group of blood married with rhesus-positive (homozygotic) woman with IV group of blood. What blood will their children have?
Solutions: (see attachment for better table representations)
1. Sex is determined by the action of genes and chromosomal traits. Sex is determined by the sex chromosomes called X and Y, which are involved in determining the sex and other traits. These X-linked traits are heteromorphic. In human, the female is represent as XX and the male is represented as XY.
In human or mammal, Alfred Jost proposed that sex determination is originated from the gonad, and differentiate sexually into the testes and ovaries. The first rule of sex determination is to develop the gonads into testis or ovary to determine the sexual differentiation of the embryo. Testosterone induces the Wolffian ducts to differentiate into epididymides, vasa deferens, and seminal vesicles. Anti-Mullerian hormone (AMH) causes regression of the Mullerian ducts, which in its absence would develop into the Fallopian tubes, uterus, and upper vagina as is observed in female embryos. The second rule of sex determination is that the Y chromosome carries the sex-determining information in mammals. There are three levels of sexual dimorphism. The genetic sex that represent a female and a male; XY (male) and XX ( female). The gonadal sex is represented by the testes and ovaries. The phenotypic sex that is female and male. Sex is determined by the presence of the Y chromosome; female is the default sex because of the absence of the Y. The testis determining factor produce the SRY gene and the sex determining region on the Y chromosome that determine the maleness of a person. The SRY gene is the male determining factor. TDF stimulates embryonic gonads to begin producing testosterone. Testosterone stimulates the differentiation of embryonic gonadal tissue into "male" structures. When the ...
Sex is determined by the action of genes and chromosomal traits. Sex is determined by the sex chromosomes called X and Y, which are involved in determining the sex and other traits. These X-linked traits are heteromorphic. In human, the female is represent as XX and the male is represented as XY.
Hormones and Sex Differentiation
The presence or absence of testosterone determines whether a mammal will differentiate as a male of female - estrogens have no effect. In birds, it is the opposite: the presence or absence of estrogen is critical. What problems would sex determination by estrogen create if that were the mechanism for mammals? Why do those problems not arise in birds?View Full Posting Details