Heredity Unit Notes Quiz #2 Content

(1) Allele Variations All individuals inherit 2 alleles per gene: 1 from mother (egg cell) 1 from father (sperm cell) Individuals can inherit: 2 of the same allele variations = “Homozygous” 2 different allele variations = “Heterozygous”

(2) Dominant vs Recessive The 2 types of allele variations are DOMINANT and RECESSIVE. Dominant Traits always show. Recessive Traits only show when 2 are inherited together.

(3) Dominant/Recessive EXamples: Example #1: A person has Dominant-Recessive… What will they LOOK like? Example #2: A person has Recessive-Recessive… What will they LOOK like? Example #3: A person has Dominant-Dominant… What will they LOOK like?

(4) PCR Chart Review A PCR Chart can be used to show the genotypes of the parents and their offspring. 1 Thick Line = 2 of the Same Alleles inherited 2 Thin Lines = 2 Different Alleles inherited

(5) Making Predictions If we know the parents’ genotypes we can… Make predictions of the possible offspring they can produce. Make predictions as to the % chance of producing different types of offspring. Example: Make predictions for 2 parents. The mom is Homozygous Recessive for a trait, and the dad is Heterozygous.

(6) Pedigrees A Pedigree is a diagram used to show how individuals in a family are related to one another. Pedigrees can show how traits are inherited in a family. We can also use pedigrees to make predictions. Parts: Squares = Males, Circles = Females Horizontal Line = Sexual Reproduction Together Vertical Lines = Offspring of Parents