In the Middle East, early cultivation began as an attempt to copy, in a less favorable environment, the dense stands of wheat and barley that grew wild in the hilly flanks. All of the following either motivated or facilitated this attempt EXCEPT:.
A) population growth.
B) climatic changes that reduced the available amount of wild wheat and barley.
C) the existence of a vertical economy.
D) human inventiveness and experimentation that occurred in the optimal zones, such as the hilly flanks.
E) living in marginal areas most affected by climatic changes.

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.

the cell is the smallest structural and functional unit of living organisms, which can exist on its own. therefore, it is sometimes called the building block of life. some organisms, such as bacteria or yeast, are unicellular—consisting only of a single cell—while others, for instance, mammalians, are multicellular.