AP BIOLOGY

Detailed explanation-1: -genotype = the genes of an organism; for one specific trait we use two letters to represent the genotype. A capital letter represents the dominant form of a gene (allele), and a lowercase letter is the abbreviation for the recessive form of the gene (allele).

Detailed explanation-2: -A Punnet square shows the genes (represented by letters) in the parents’ gametes along the top and left-hand side of a square and the possible gene combinations in the offspring, within the square. A completed Punnett square gives the probable outcome of a given cross.

Detailed explanation-3: -A Punnett square is a chart that allows you to determine the expected percentages of different genotypes in the offspring of two parents. A Punnett square allows the prediction of the percentages of phenotypes in the offspring of a cross from known genotypes.

Detailed explanation-4: -When discussing genotype, biologists use uppercase letters to stand for dominant alleles and lowercase letters to stand for recessive alleles. With eye color, for instance, “B” stands for a brown allele and “b” stands for a blue allele.

Detailed explanation-5: -What do the letters in each box of the Punnett square tell you? The possible combinations of alleles in offspring based on parents’ genetic makeup.