Answer:
The following statements are true and are relevant to The Cell Theory:
B. all living things are composed of cells.
E. all cells arise from preexisting cells
F. the cell is the fundamental unit of life.
Step-by-step explanation:
Although lower percentage of atmospheric oxygen in earlier times (220 million years ago) is true, it is not possible that the ratio was "much larger" than what it is today.
Option C is correct but not pertinent to the cell theory. Viruses are considered as living things once they are inside a host.
G1 and G2 are growth phases and have the same amount of DNA in them. It is during the mitotic phase that the DNA is increased. Hence, option D is incorrect.
Option G is false as well. Prions are not considered as living things, they are just proteins that can cause infections.
Hope that answers the question, have a great day!