Acid I think is the correct answer
I’m your teacher and you shouldn’t put questions that are personal
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>
Answer:
Although an individual gene may code for a specific physical trait, that gene can exist in different forms, or alleles. ... In other cases, each parent provides a different allele of a given gene, and the offspring is referred to as heterozygous ("hetero" meaning "different") for that allele.
Answer:
Oxygen and pyruvate.
Explanation:
The krebs cycle is a stage of cellular respiration and occurs in aerobic organisms. In this case, we can say that the Krebs Cycle only occurs in the presence of oxygen, being essential for the completion of cell respiration.
The Krebs cycle only occurs after the completion of glycolysis, as it needs to be initiated by pyruvate, which is a molecule resulting from glycolysis. In this case, in addition to oxygen, the presence of pyruvate is essential for the krebs cycle to occur.
