Genes come in different varieties, called alleles<span>. </span>Somatic cells<span> contain two alleles for every gene, with one allele provided by each parent of an organism. It is impossible to tell exactly what gene the organism could have. </span>
Answer: Mesopotamia, china, indus River Valley, the mesoamerican empires..... in this case, the two rivers are the tigris and Euphrates. Mesopotamia. The name Mesopotamia was given to the middle eastern civilizations that existed between the Euphrates and Tigris Rivers. :)
The answer is A. are specialized. Hope this helps
