The structure labeled “X” represents: a) A tetrad
b) daughter cells
c) DNA replication

enhanced global partnerships and exploration capabilities may advance international preparedness for protecting the earth from catastrophic events such as some asteroid strikes, advancing collaborative research on space weather and protecting spacecraft by developing new means for space debris removal.

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.