# The Work of Gregor Mendel

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The Work of Gregor Mendel
Chapter 11-1

Set up Cornell Notes 11-1 The Work of Gregor Mendel

Gregor Mendel Austrian live in the mid 1800’s Born to peasant farmers
Became a monk and lived in a monastery

Gregor Mendel “Father of Genetics” Experimented garden plants and small farm animals to understand genetics. Known mostly for his experiments with pea plants

Genetics Scientific study of heredity
The study of how parents pass down traits to their offspring

Inheritance The passing of traits from parents to offspring.

Mendel’s Experiments Mendel Cross Pollinated Pea Plants and Studied how their traits were passed from 1 generation to the next Kept DETAILED records (Data) Analyzed data and came up with conclusions that eventually were turned into the laws of genetics

Mendel and Hawkweed

Trait Specific characteristic that varies from one individual to another Traits Mendel looked at: Mendel started with purebreds and all offspring came out looking like their parents. Short

What is Probability? Question: If I toss a penny 50 times, how many times will it land on heads? Hypothesis: Data: Heads Tails Totals: %Heads & %Tails Conclusion:

Probability Question: If we add up all of the coin tosses in the class, what do you think the percentage of times did the pennies land heads? Hypothesis: Data: Totals % heads tails Conclusion:

Probability Question: If we add up all of the coin tosses in all of Ms. Hau’s classes, what do you think the percentage of times did the pennies land heads? Hypothesis: Data: Totals % heads tails Conclusion:

Probability It’s the likelihood that an event will happen
Its Not Exact One event does not affect the next The more times you repeat an event the more likely you’ll get closer to your predicted outcome.

Purebred/ Homozygous TT = tall & tt = short
Genetically pure for a particular trait. Both genes are the same for a trait. Offspring Parents TT = tall & tt = short

What do you think the outcome was?

Hybrid / Heterozygous Tt = Tall Have two different forms of a gene
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Gene A segment on a chromosome consisting of a long sequence of nitrogen bases that code for a protein. (Proteins do the work in cells and determine traits)

Allele OR Example: Gene for Plant height -Allele for Tall OR
Different form of a gene OR Example: Gene for Plant height -Allele for Tall OR -Allele for Short OR OR

Mendel’s Principle of Dominance
States that some alleles are dominant and others are recessive.

Dominant Allele The stronger form of a gene.
Represented by the capital letter of the dominant trait. (T=tall) If present will be the trait that is expressed.

Recessive Allele The weaker form of a gene.
Is represented with a lower case letter. (t=short) Recessive trait hides unless both genes are the recessive allele.

Genetic Data Collection
P- generation F2- generation F1- generation The first set of parents were called the “P” generation The resulting offspring were called the “F1” generation The offspring of the F1 generation were called the “F2” generation

Gamete Sex cells (Egg & Sperm)

Fertilization When male and female reproductive cells join
Egg & Sperm Or Pollen & Egg

Zygote Fertilized Egg

Segregation All living things contain 2 genes for every trait, one from their mother and one from their father During production of sex cells the chromosomes separate so that each gamete have only 1 set of chromosomes

Crossing 2 Hybrids: