I believe the answer is During<span> prophase
</span>The nucleus during mitosis. Micrographs illustrating the progressive stages ofmitosis<span> in a plant cell. </span>During<span> prophase, the chromosomes condense, the </span>nucleolus<span>disappears, and the </span>nuclear envelope<span> breaks down. At metaphase, the condensed chromosomes </span>
Answer: <em>The Bottleneck Effect</em>
Explanation:
A Bottleneck effect is the sharp reduction of numbers of a population through environmental effects or human activity. It causes a loss of the genetic pool and its variety; genetic variation lowers and increases with time as random mutations occur.
Produce energy usable by the cells of their respective organisms.
The answer should be proteins. Because the protein is consists of different kinds of amino acids(usually 20 in total). And our cell can not produce essential amino acids itself.