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Explore Gregor Mendel's groundbreaking work in genetics, including his study of pea plants, the traits he studied, and his laws of inheritance. Understand the concepts of genotype, phenotype, alleles, and dominant vs. recessive traits. Solve sample problems to practice Punnett squares and determine probabilities of offspring traits.
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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.
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 • Parents • Pure – • F1 Generation • Hybrid – 2 different types of genes for a trait • F2 Generation • 3:1–Yellow : Green
Definitions • Genetics: • Study of hereditary • Gene: • Strand of DNA that codes for a protein (Trait) • Allele: • A version of a gene
Phenotype vs. Genotype • Phenotype: • Physical characteristics (What the individual looks like) • Ex) Red Petals • Genotype: • Alleles Received (genes you have) • Ex) RR
Homozygous and Heterozygous • Homozygous: • Having two of the same alleles for a particular trait • Ex. • Heterozygous: • Having two different alleles for a particular trait • Ex.
Dominant Vs. Recessive • Dominant hides the recessive trait in the heterozygousgenotype.
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 Sperm 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
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
R r R r Monohybrid Cross • R= Can roll your tongue • r= Can’t roll your tongue • Genotype Ratio: • Phenotype Ratio:
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.