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>
It would be generation 5 in which there will be almost 100% non-singing females if there are no changes in the birds’ environment and interactions
Answer:
Cellular respiration takes place in mitochondria of a cell, hence it is also known as power house of cell , because it gives us energy in the form of ATP molecule .