Genetics

YouTube - Mr. Lee - Genetics rap

homozygous 2 of the same alleles for a trait examples: P P, p p, T T, t t

Punnett squares are tools to help geneticists predict the probability of certain traits in offspring by showing all of the ways the parents’ alleles can combine

heredity the passing of traits to offspring (children, young, descendents)

genes the factors or substances that control traits

genetics the study of heredity

heterozygous 2 different alleles for a trait examples: P p, T t

offspring the new organism produced by a parent or parents (ex: children, young; synonym: descendents)

alleles the different forms of a gene G G G g g g G and g

Gregor Mendel “Father of Genetics” An Austrian monk who studied the traits of pea plants

recessive allele an allele that is hidden when a dominant allele is present; can be masked by another allele These characteristics only “show up” if both alleles for a trait are this type. t

genotype the genetic makeup of an organism that determines the phenotype the allele combination (letters representing dominant and recessive alleles) ex. PP

traits characteristics that parents can pass to offspring (ex: eye color, hair color, shape of eyebrows)

phenotype a physical trait of an organism (what it looks like) ex. purple flower

another way to refer to homozygous genotypes purebred another way to refer to homozygous genotypes 2 of the same alleles for a trait examples: P P, p p, T T, t t

dominant allele an allele that can mask another allele and always “shows up” if present T

another way to refer to heterozygous genotypes hybrid another way to refer to heterozygous genotypes 2 different alleles for a trait examples: P p, T t

probability the relative possibility that an event will occur