Wall of blood vessel is one cell thick
a. artery
b. capillary
c. vein

the answer to the blank provided is “an autosomal gene that is required for the expression of genes on the x chromosome”.

testis-determining factor, abbreviated as td, which is more popularly known as sex-determining region y or sry protein, is a dna-binding protein or  gene-regulatory protein/transcription factor, encoded by the  sry gene. it is the gene responsible for the initiation of male gender determination in humans.

answer is d hope this

a ratio derived from the equality between two different units that can be used to convert from one unit to the other. information obtained from experiments, sometimes called experimental results. the part of the experiment that is affected by the independent variable.