Note: Content may be edited for style and length. This mechanism thus reduced the level of female expression of genes on the X chromosome to the same level as that in an XY male. Collins, M. Explanation : This trait is X-linked, which can be determined by considering individual 4.
These studies, a detailed analysis of the X chromosome's DNA sequence and a survey of its gene activity, are published in the current issue of the journal Nature.
However, not all female carriers present these symptoms. Specifically, the researchers determined that due to the incomplete nature of X-inactivation, at least 15 percent of genes on the X chromosome produced proteins at higher, often variable, levels in females than in males. The dominant X chromosome is represented as X R.
However, not all female carriers present these symptoms.
A team of researchers studying the Possible Answers:. So, Jacob must inherit one of his mother's healthy X chromosomes, and there is no chance that he will be colorblind. Eggs fertilized by sperm with a Y chromosome become males.
X-linked recessive genes are expressed in females only if there are two copies of the gene one on each X chromosome. Despite its relatively low gene density, the X chromosome holds a prominent place in the study and understanding of human disease. Correct answer: X-linked.
However, in the late s, researchers learned that some fraction of the genes remain active. Hemophilia A accounts for most cases. A team of researchers studying the Researchers say this may reflect a low density of genes on the ancestral chromosome that gave rise to the X chromosome, or it may indicate that genes coding for key proteins that are required in double dose were transferred from the X chromosome to other chromosomes during the course of mammalian evolution.