Chapter 9. Who’s the Father of Modern Genetics ?. Gregor Mendel!. 1843: Austrian monastery Job = gardening 1851: University of Vienna Studied math and science Statistics!!!. What did Mendel Experiment with?. What plant? What about these plants?

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Chapter 9

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Who’s the Father of Modern Genetics? Gregor Mendel! • 1843: • Austrian monastery • Job = • gardening • 1851: • University of Vienna • Studied math and science • Statistics!!!

What did Mendel Experiment with? • What plant? • What about these plants? • Characteristics- heritable feature • Traits- genetically determined variant of a characteristic

Mendel’s Observations • Seeds from purple flowers produce... • Seeds from white flowers produce... • Seeds from tall plants... • Seeds from short pants... • This always true? NO!!!

Mendel’s Conclusions • What did he conclude? • Something in the plant was a controlling factor • What Did Mendel Hypothesize About Passing Traits? • Each trait independently controlled

Conclusions: LAWS • Law of segregation • Pair of factors are separated during production of gametes. • Why/How? • Online Animation!

Conclusions: LAWS • Crossed plants w/2 different characteristics (flower color, seed color) • Offspring showed traits from dominant factors of each • Law of Independent assortment • characteristics are inherited independent of each other • Another Great Animation!

Pp Yy PY Py pY py Purple flower Yellow seed Purple flower Green seed White flower Yellow seed White flower Green seed

Pair Share! • 1st person: explain the Law of Segregation • 2nd person: explain the Law of Independent Assortment

Support for Mendel’s Conclusions Molecular Genetics Study of structure and function of genes and chromosomes “Factors” are now called ALLELES!

Gene vs. Allele Piece of DNA Transcribed proteins Several on each chromosome • Variants of genes • Represented by letters Symbols: • Dom (capital)/Rec (small) • Flower color: P and p • Dom means... • Rec means...

YES!!!! Can different genotypes show the same phenotype?

Homozygous and Heterozygous Refer to genotypic or phenotypic? Homozygous Both alleles are SAME AA or aa Heterozygous Alleles are DIFFERENT Aa

What’s PROBABILITY? # of times expected Probability = # of times could happen Likelihood of something happening Percent, decimal or fraction

PROBABILITY PRACTICE = • 1000 plants • 700 terminal flowers • 300 axial flowers • What is the probability that the next plant will have terminal flowers? • Axial?

What’s a MONOHYBRID CROSS? eggs sperm • Only one characteristic is tracked • Produces a mono-hybrid • AA x aa Aa • What’s a Punnett Square? • Diagram used to predict probabilities of inherited traits in offspring

6 types of monohybrid crosses: Homozygous x Homozygous Homozygous x Heterozygous Heterozygous x Heterozygous Testcross Incomplete Dominance Codominance

Hom. Dom. x Heterozygous Black guinea pigs (dom), brown (rec) What genotypes? Probability for Black? Homozygous? Heterozygous?

Testcross: animation What genotype do you test it with? Hom recessive x Unknown genotype You are Given a Black Guinea pig. How do you determine the Genotype? If you end up with three black guinea pigs and one brown what was the genotype of the unknown guinea pig?

OPENER, Wed. 12/2 You’re TURNING THIS IN, in 7 minutes!! Use “D” and “d” for the alleles, make a punnett square for each: D = Dodo Head d = Wiz Kid 1. Purebred Dodo Head x Wiz kid 2. Heterozygous x Wiz kid 3. Hybrid Dodo Head x Homozygous Dodo Head Then, for each scenario, find the probability of: a. Dodo Heads? b. Wiz Kids? c. Purebred Dodo Heads d. Heterozygous offspring

OPENER, Wed. 12/2 You’re TURNING THIS IN, in 7 minutes!! Use “D” and “d” for the alleles, make a punnett square for each: D = Dodo Head d = Wiz Kid 1. Purebred Dodo Head x Wiz kid 2. Heterozygous x Wiz kid 3. Hybrid Dodo Head x Homozygous Dodo Head Then, for each scenario, find the probability of: a. Dodo Heads? b. Wiz Kids? c. Purebred Dodo Heads d. Heterozygous offspring

OPENER, Wed. 12/2 You’re TURNING THIS IN, in 7 minutes!! Use “D” and “d” for the alleles, make a punnett square for each: D = Dodo Head d = Wiz Kid 1. Purebred Dodo Head x Wiz kid 2. Heterozygous x Wiz kid 3. Hybrid Dodo Head x Homozygous Dodo Head Then, for each scenario, find the probability of: a. Dodo Heads? b. Wiz Kids? c. Purebred Dodo Heads d. Heterozygous offspring

OPENER, Wed. 12/2 You’re TURNING THIS IN, in 7 minutes!! Use “D” and “d” for the alleles, make a punnett square for each: D = Dodo Head d = Wiz Kid 1. Purebred Dodo Head x Wiz kid 2. Heterozygous x Wiz kid 3. Hybrid Dodo Head x Homozygous Dodo Head Then, for each scenario, find the probability of: a. Dodo Heads? b. Wiz Kids? c. Purebred Dodo Heads d. Heterozygous offspring

Monohybrid Cross Lab • Alleles, gametes, genotypes, phenotypes, Punnett Squares, & probabilities • Write your BAG #s on your data sheet! • COUNT all of your pieces before you begin • You’re drawing from the bags FORTY times today...get going! Follow the directions CAREFULLY! • We’ll finish up after the lab with more examples.