a. respiration of living organisms
D. absorption of CO2 from the atmosphere by ocean water
Answer:
Explanation:
Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). DNA safely and stably stores genetic material in the nuclei of cells as a reference, or template. Meanwhile, mRNA is comparable to a copy from a reference book because it carries the same information as DNA but is not used for long-term storage and can freely exit the nucleus. Although the mRNA contains the same information, it is not an identical copy of the DNA segment, because its sequence is complementary to the DNA template.
For giving you understanding ; we need Free O2 but Oxygen is also available in H20 right why dont we use it !!
As the early atmosphere was reducing as there was no free oxygen but it was later produced by chemoautotrophic bacteria !! Living thing release O2 in atmosphere thus making it oxidising in nature and then life evolves !!
I believe the answer is respiration