The correct answer is D.
From the scientific research conducted so far, we know that in the early Earth's history the atmosphere lacked oxygen and was mostly filled with other gases like methane. The increase in oxygen levels happened when the plants started producing oxygen as a byproduct of the process of photosynthesis.
The research so far also shows that the RNA was present before the DNA and that the microspheres might have been essential to the development of life on Earth.
NAD +molecule
Explanation:
Krebs cycle and electron transport chain are important steps in cellular respiration.
In the Krebs cycle, there is a need of NAD+ molecule which is then in Krebs cycle reduced to form a NADH2 molecule.
NADH2 is also an energy currency. It , giving electron in electron transport chain and return to Krebs cycle as NAD+.
Now in the Krebs cycle, it is ready to take electrons again.
Answer:
It affects populations, It occurs when there is genetic variation, It selects organisms with certain traits to survive. I'm not 100% sure this is completely correct, but I just studied this in school and this sounds right. :)
Answer:
A lapse rate is a rate during which the temperature changes with the peak within the atmosphere.
Explanation:
sorry it took me so long :(
I just took the test. The answer is climate
