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?© BrainMass Inc. brainmass.com March 21, 2019, 11:51 pm ad1c9bdddf
In mammals, the SRY gene, which is located on the Y-chromosome, codes for the production of testosterone. Only males possess the Y-chromosome. Females have two X-chromosomes, while males have one X and one Y chromosome. The hormone estrogen is coded for by a gene located on the X-chromosome. Initially, human beings are gender-neutral; all ...
The expert examines hormones and sex differentiation. The presence or absence of testosterone determines whether a mammal will differentiate as a male of female - estrogen have no effect.