A. Most recent period of the Cenozoic era.
The correct answer to this question is this one: they lacked oxygen. The earliest organisms were completely heterotrophic in nature because of the reason that they lacked oxygen. <span>A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. </span>
Reaction which breaks down complex molecules into simpler ones n release energy
Answer:
Ribosomal RNA (rRNA) associates with a set of proteins to form ribosomes. These complex structures, which physically move along an mRNA molecule, catalyze the assembly of amino acids into protein chains. They also bind tRNAs and various accessory molecules necessary for protein synthesis.
Explanation:
Populations tend to grow because of repopulation.