The correct answer to this question is this one: they lacked oxygen. The earliest organisms were completely heterotrophic in nature because of the reason that they lacked oxygen. <span>A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. </span>
Nerve, Skin, Cyclins, Cancer
<span> c)atp has three phosphate groups, while adp has two phosphate groups. </span>
When our red-sensitive nerves in our eyes cannot respond to light properly this will result in color blindness - b.
When either of the three light-sensitive nerves in our nerve tracts; either green, red or blue, we become to color blind for a certain spectrum of light from nature.
<span>The migration routes of Homo sapiens reveal
that they went through many environmental and physical challenges but adapted
everything much quickly in comparison to the other animals. The evolution
allowed other species also to adopt these changes but it took them a long time
to fit in the new environment, a sub species of a species adopted the new and
the previous one could not, but Homo sapiens invented ways and tools to combat
and evolve much quickly. It included their living, dietary needs, clothing and
much more.</span>
