For most genes on the human x chromosome, what percent of xy males with a mutant allele on the x chromosome will express the mutant phenotype?

a., 0%
b., 25%
c., 50%
d., 100%
e., there is insufficient data to predict

D. 100%

Explanation:

In humans, males have only one copy of the X chromosome in their cells. Therefore, human males express all the X-linked genes present on their X chromosomes irrespective of the recessive or dominant nature of the allele. This occurs since males do not have one more copy of the X chromosome to carry another allele for the gene. So, all the X-linked alleles present on the X-chromosomes of the human males are expressed.

For example, human males with genotype X^cY and X^hY express colorblindness and hemophilia respectively. Though, human females express these recessive X-linked disorders in homozygous genotype only.

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this