Hydrogen would be the answer to this.
Answer:
<em>This is an example of natural selection (adaptation).</em>
Explanation:
Natural selection tends to favor those organisms which are better adapted to live in an environment.
As tortoises having flat shell and long neck were better adapted to live in barren area, hence through natural selection those organisms were favored in such an ecosystem.
As tortoises that lived on the vegetative lands were more adapted to live in such an ecosystem, hence through natural ecosystem these organisms were favored and increased in numbers.
Answer:
nitrogen fixation.
Explanation:
Nitrogen fixation is the process by which the combination of molecular nitrogen oxygen or hydrogen is given to give oxides or ammonium that can be incorporated into the biosphere. Molecular nitrogen, which is the majority component of the atmosphere, is inert and not directly usable by most living beings.
<span>D) composed of one or more eukaryotic cells</span>
