<span>The space-filling model of a hydrogen molecule would be something like OO , two circles stuck to each other, even squished a little bit. The model for carbon dioxide would be like OOO, with the two circles on the sides a little bigger and squished into the middle circle. </span>
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 !!
They allowed scientists to study heredity and further develop it
Answer:
I believe it's D. asexual reproduction
