Easy. Answer is oxygen because it says which one was missing before any life was on earth. And in order to have life on earth you need oxygen!
:)
3, 1, 2, 5, 4. :-) I hope this helped. DNA is the smallest and the atmosphere is the largest.
Answer:
Maintains successful genetic combinations without modification.
Explanation:
Asexual reproduction usually creates perfect copies of the parent. If the parent is genetically sound creature, then a successful genetic combination is being reproduced and maintained without any changes or modification.
A cladogram is a chart which demonstrates cladistics. A branch point on a cladogram branches off from a common point in a cladogram, which shows that the two organisms share a common ancestor. Hope this helps! (: