<span>The control would be a plant grown without any fertilizer. This is called a negative control and is important in identifying the influence of the treatments on the tests. In this case, it would mean that the plant without fertilizer (control) is not expected to grow as large as in the other treatment. </span>
Mushrooms because they belong in the fungi kingdom
(1) All the genotypes are as follows: AABB, AaBB, AABb, AaBb, aaBB, aaBb, AAbb, Aabb, aabb.
(2) Assuming that Aa is dominant and Bb is recessive, there will be 9 phenotypes with both A and B allele dominant (i.e. AaBb, AABb); there will be 3 phenotypes with just the A allele dominant (i.e. Aabb, AAbb); there will be 3 phenotypes with just the B allele dominant (i.e. aaBb, aaBB); and there will be 1 phenotype with both alleles recessive (i.e. aabb). The phenotypic ratio in this case is 9:3:3:1.
(3) The probability of producing an offspring with the aabb genotype is 1/16 or 6%.