What Is Life? 2nd Edition by Jay Phelan

تمرين 10

Of all the varying types of sex chromosome abnormalities, one possibility-that of an individual having one Y but no X-has never been reported. Which of the following statements is the most likely reason that medical researchers have yet to report a person having a karyotype with one Y and no X?
A) There is no meiotic event that could produce an egg that does not have an X chromosome.
B) Individuals are probably born with this karyotype; however, because the phenotypic abnormalities caused are so slight, they live out their lives normally and are unaware of this genetic anomaly.
C) The Y chromosome needs the X chromosome to be present in the cell in order for its genes to be expressed.
D) The X chromosome contains genes that are unrelated to sex determination and are essential for life.
E) Our current technology for karyotyping would not reveal such an abnormality. Short-Answer Questions