<span>A
gradual change in phenotype over a geographical area is called a cline (or clinal variation).</span>
A
cline is gradual phenotypic (and/or genetic) differences over a geographical
area. It usually happens as a result of the change of allele frequencies within
the gene pool.
Answer:
The amino acids are important for the growth of almost all the organisms from the yeast to humans. While culturing yeast at the lab conditions, proper growth media is required.
The yeast is not able to make leucine. When this yeast is grown in the YPD plate, the growth of yeast is supported. The YPD consists of peptones, glucose and yeast extract. This media is enriched with all the components required for the yeast growth. The SD plate is also known as synthetic plate that do not contain the essential amino acids and consists of only nitrogenous bases. The mutant yeast will unable to grown in this media as leucine is not available. The mutant can be grown on this plate if the plate is supplied with the external media consisting of leucine and other essential amino acids.
<span>Plant cells will also change with the degree of specialization. It means that when is is a higher developed organism then it will have a higher degree of specialization. For the second question,Somatic cells of animal callus are most common to the plant cell. It is because just like a callus, the tissue of the plant cells are thick and it serves them as protection from friction.</span>
