AP BIOLOGY

Detailed explanation-1: -Because only males have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and development. Sex is determined by the SRY gene, which is responsible for the development of a fetus into a male.

Detailed explanation-2: -The Y chromosome contains a “male-determining gene, ” the SRY gene, that causes testes to form in the embryo and results in development of external and internal male genitalia. If there is a mutation in the SRY gene, the embryo will develop female genitalia despite having XY chromosomes.

Detailed explanation-3: -These girls do not discover anything different until puberty. “Girls born with XY chromosomes are genetically boys but for a variety of reasons – mutations in genes that determine sexual development – the male characteristics are never expressed.

Detailed explanation-4: -The syndrome is commonly known as Jacob’s syndrome, Superman syndrome, XYY karyotype, XYY syndrome, YY syndrome, and 46, XY/47, XYY mosaicism. The genetic alteration occurs in one out of 1, 000 male babies and can be traced back 100, 000 years to one male ancestor.