This is called incomplete dominance. When an something is heterozygous for an incomplete dominant gene, the resulting phenotype will be somewhere between the two. For example if a plant has a tall allele and a short one, but neither shows complete dominance over the other, the plant height will be somewhere in the middle.
DNA isolation is a process of purification of DNA from sample using a combination of physical and chemical method while on the other hand, Polymerase chain reaction (PCR<span>) is a technique used in molecular biology to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.</span>
Because for one plants reproduce a lot more than animals by up to 100 seeds coming from each plant. Also if there were more animals plants would run out.