Whats is the most common gas in earths atmosphere

Nitrogen — 78 percent.

Oxygen — 21 percent.

Argon — 0.93 percent.

Carbon dioxide — 0.04 percent.

Remaining are trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor.

Therefore, Nitrogen is  most abundant.

Explanation:

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.