Gregor Mendel

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Gregor Mendel

Students will be able toDescribe the results of Mendel’s experiments

Identify what controls the inheritance of traits in organisms

Genetic TermsHeredity

The passing of physical characteristics from parents to offspring

GeneticsThe study of heredity

CharacteristicsObservable items on a living thing

Hair color, Height, Weight…Trait

A different form of a characteristicExample – Hair Color

Blond, Brown, Red, …

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Mendel’s chart

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Mendel’s Experiment

• Breeding pea plants• Female part (eggs) = Pistil• Male part (pollen/sperm) = Stamens

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Breeding

• Purebred organism = offspring of many generations that all have the same trait.

• Hybrid organism = mixed traits

Experimental Definitions• P = Purebred parents• F1 Generation = Children of purebred parents

• F2 Generation = Grandchildren of parents

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Experiment

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Offspring

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Offspring

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Terminology

Gene

Something that determines what trait you have

Example: You have blue eyes because you gene that controls eye color

Allele

Different forms of a gene

Example:

Blue eyes because your eye color gene is blue

“Blue Allele”

Brown eyes because your eye color gene is brown

“Brown Allele”79

Symbols

• Dominate trait is always capital letter• Recessive trait is same letter as dominate letter

but lower case

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Numbers of Alleles

Get two alleles for each gene

One from Mom

One from Dad

Purebred have both alleles the sameHybrid have a different allele from each parent

Get one version from dad and a different one from mom

Experiment

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Offspring

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Mendel

Completely unknown in his time

Work was lost for several decades

Only rediscovered in recent history

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Question of the Day

Describe in your own words what happened when Mendel bred the two pea plants. In your essay include the P, F1, F2 generations.

4 3 2 1

100% 80% 60% 40%

Exceeds expectations

Required Work

Missing a few items

Missing many items

The Test Cross

• P Generation

H = Short Hair

h = Long hair

H? hh

F1 Generation

H? hh

H? hh H? H?

Horses

Black coat (B) is dominate

Brown coat (b) is recessive