AP BIOLOGY

Detailed explanation-1: -Recessive alleles are denoted by a lowercase letter (a versus A). Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait.

Detailed explanation-2: -Dominant is always a capital letter and Recessive is always a lower-‐case letter. Here is where I write down the letters that represent my couple. Because they are heterozygous, I use one capital letter and one lower letter since they have both traits in their genes.

Detailed explanation-3: -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-4: -An organism with one dominant allele and one recessive allele is said to have a heterozygous genotype. In our example, this genotype is written Bb. Finally, the genotype of an organism with two recessive alleles is called homozygous recessive. In the eye color example, this genotype is written bb.

Detailed explanation-5: -Heredity. In a Punnett square, capital letters represent dominant alleles. Lower case letters represent recessive alleles.