I think the correct answer from the choices listed above is option A. Directional selection can be distinguished from disruptive selection by the elimination of extreme variations of traits. Directional selection is a natural selection where an extreme phenotype is favored than others.
The nucleotide sequence would have to have 900 nucleotides in order to code for a protein of 300 amino acids. When translating RNA into proteins, RNA is read 3 bases at a time. Each group of 3 bases is a codon, and each codon codes for an amino acid. When read, the proper amino acid is added to a growing chain of amino acids, which will be folded to become a protein.
Therefore, 300 amino acids * 3 nucleotides per amino acid = 900 nucleotides.
<span>Heterotrophs, organisms that must get energy from food indirectly from sunlight or inorganic substances, go through the process of cellular respiration to get the energy needed.</span>
Methane, overview, carbon dioxide, Fluorinated Gases
You see first the light wave because light travels faster than sound. Hope this helps