Why do males have only one allele for all genes on the X chromosome

Atypical human cell is approximately 12.00 μm in diameter and enclosed by a membrane that is 5.000 nm thick. (a) what is the volume of the cell including the membrane? (b) what is the volume of the cell membrane? (c) what percent of the total volume does its membrane occupy? to simplify the calculations, model the cell as a sphere. enter your answers using four significant figures.

Which of these is most likely to happen if parallax measurements of star distances are taken after a gap of six months? the results would be accurate the results would be inconsistent the results would not be valid the results would not be repeated

Which of these is not a nucleotide base found in dna?