Genetics Chapter 10.2, 10.3, 11.1, and 11.2

WARM UP 12-1-16 Complete Mitosis vs. Meiosis worksheet 2 extra points on final exam for anyone who can correctly complete it before the bell rings! This will go on page 45 of your notebook

1866 Gregor Mendel “Father of Genetics” Austrian Monk that studied pea plants Pure breeds Self Fertilization Statistician who wanted to be a teacher Discovered how traits were inherited in a population

How Genetics Began The passing of traits to the next generation - inheritance or heredity. Mendel performed cross-pollination in pea plants. Mendel followed various traits in the pea plants he bred.

7 Traits Mendel Studied

Mendel studied seven different traits. Seed or pea color Flower color Seed pod color Seed shape or texture Seed pod shape Stem length Flower position

Mendel’s Crosses P Generation: F1 Generation: F2 Generation:

Generations P Generation F1 Generation F2 Generation Parents Pure – Hybrid – 2 different types of genes for a trait F2 Generation 3:1–Yellow : Green

Definitions Genetics: Gene: Allele: Study of hereditary Strand of DNA that codes for a protein (Trait) Allele: A version of a gene

Phenotype vs. Genotype Phenotype: Genotype: Physical characteristics (What the individual looks like) Ex) Red Petals Genotype: Alleles Received (genes you have) Ex) RR

Homozygous and Heterozygous Having two of the same alleles for a particular trait Ex. Heterozygous: Having two different alleles for a particular trait

Dominant Vs. Recessive Dominant hides the recessive trait in the heterozygous genotype.

Think – Pair - Share If Fred Flintstone is heterozygous for black hair. (B=Black, b=blonde) What is Fred’s genotype? What is Fred’s phenotype? Tweety bird is yy. (Y= yellow feathers, y=brown feathers) 1. What is his genotype? 2. What is his phenotype? 3. Is he heterozygous or homozygous? Explain.

w W W w Mendels 3 Laws 1. Law of Segregation Each allele a person has separates into different gametes Ex. Ww – one W goes in one sperm and the other w goes into another sperm w W w W Sperm

Mendels 3 Laws 2. Law of Independent Assortment Gene pairs (homologous) will separate randomly into gametes

Mendels 3 Laws 3. Law of Dominance Traits exist in two possible forms (dominant and recessive) The dominant forms hides the recessive trait in the heterozygous condition

Monohybrid Cross R= Can roll your tongue r= Can’t roll your tongue Genotype Ratio: Phenotype Ratio: R r

Genotypic vs. Phenotypic Ratios Phenotype Ratio: Ratio of different physical traits Ex) Brown eyes ¼ or 25% Genotype Ratio: Ratio of the different possible alleles Ex) Tt = ¼ or 25%

Sample Problems Daffy Duck is heterozygous for black feathers. Daisy Duck is homozygous for yellow feathers. Set up a punnett square and determine probabilities of their potential offspring. (Both genotype and phenotype ratios!) B = Black b = yellow

Do Now Sponge Bob Square pants is heterozygous for brown eyes. Sandy is also heterozygous for brown eyes. Create a punnett square to determine the possible outcomes of their children.

Do Now Sleeping Beauty has freckles. Her prince charming is heterozygous for no freckles. What are the chances of her children having freckles? Please show your work.