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Do Now- True for False if false, correct the statement. 1. Certain acquired characteristics, such as mechanical or mathematical skill may be inherited . 2. Certain thoughts or experiences of a mother mark or alter the hereditary makeup of an unborn child.
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Do Now- True for False if false, correct the statement. • 1. Certain acquired characteristics, such as mechanical or mathematical skill may be inherited. • 2. Certain thoughts or experiences of a mother mark or alter the hereditary makeup of an unborn child. • 3. Color blindness is more common in males than in females. • 4. A person may transmit characteristics to offspring which he/she does not show. • 5. Certain inherited traits may be altered by the stars, planets or moon early in development. • 6. The total number of male births exceeds female births each year.
Genetics Chapter 10.2, 10.3, 11.1, and 11.2
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 – the parent generation • Parents • Pure • F1 Generation – the offspring or generation produced by the P Generation • Hybrid – 2 different types of genes for a trait • F2 Generation – the offspring or generation produced by the F1 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 • Heterozygous: • Having two different alleles for a particular trait
Dominant Vs. Recessive • Dominant gene is represented by a capital letter • Example - T • Recessive gene is represented by a lower case letter • Example - t • Dominant hides the recessive trait in the heterozygousgenotype • Example – T=Tall and t=short • A person with the genotype Tt would be Tall but they would also carry the short gene to pass on to offspring.
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.
R r Sperm Mendels 3 Laws • 1. Law of Segregation • Each allele a person has separates into different gametes • Ex. Rr – one R goes in one sperm and the other r goes into another sperm r R
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
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%
R r R r Monohybrid Cross • R= Can roll your tongue • r= Can’t roll your tongue • Genotype Ratio: • RR = 1:3 or 25% • Rr = 2:2 or 50% • Rr = 1:3 or 25 % • Phenotype Ratio: • Can roll tongue = 3:1 or 75% • Cant roll tongue = 1:3 or 25% RR Rr Rr rr