1. Intro to Genetics Objectives: Differentiate b/t genotype and phenotype
Differentiate b/t homozygous and heterozygous

2. What is Genetics?
The scientific study of heredity

3. Gregor Mendel Born in 1822 in Czechoslovakia 1843—became a monk
Taught biology… 
Studied at the University of Vienna

4. More about Mendel Loved studying the garden at the monastery
Between the years of 1856 and 1863 he grew and tested of 28,000 pea plants
Used pea plants b/c they are easy to grow and they have easily identifiable traits

5. Mendel’s Experiments
Mendel created a “pure” generation or true-breeding generation (first generation)
Made sure that certain plants were only able to self pollinate to eliminate unwanted traits
He cut off the stamen (male part) of each flower

6. Genes and Dominance Trait: a characteristic Mendel studied 7 traits
After he was sure the true breeding generation was “pure” he crossed plants with contrasting traits
This was called the F1 generation

7. Pure Yellow/Pure Green
All offspring were yellow
Hybrids—the offspring of crosses between parents with contrasting traits

8. Conclusion
Inheritance is determined by factors passed on from one generation to another
Mendel know nothing about chromosomes, genes or DNA
Why?

9. Mendel’s Factors Genes Each gene has different forms called alleles
Mendel’s second principle stated that some alleles are dominant and some are recessive

10. Mendel’s Second Cross
Allowed the F1 generation to self-pollinate to produce the F2 generation
What happened in this cross?
What would happen when he crossed two yellow pea hybrids?

11. Results
¾ of the peas were yellow, ¼ of the peas were green

12. Probabilitity The likelihood of a particular event occurring. Chance
Can be expressed as a fraction or a percent

13. Genotypes Homozygous—when an organism possesses two identical alleles.
YY or yy
Heterozygous—when an organism possesses different alleles Yy

14. Genotype vs. Phenotype Genotype: Phenotype: Genetic makeup
Symbolized with letter
Tt or TT (any letter works)
Phenotype:
Physical appearance of the organism
Expression of the trait
Short, tall, yellow, smooth, etc…

15. A-angry B-Big C-cool D-Dense E—energetic a-happy b-small c-hot d-intelligent e--tired
Genotype
Phenotype Aa
Bbcc BB
Eebbcc Cc
Happy, cool, intelligent EE
Dense, hot, angry
Energetic
ddEeCC
Happy
aaCcdd
aaEE
Small, hot, tired, intelligent
Small, dense
Angry, intelligent, energetic, cool

16. Homozygous vs. HeterozygousBB Bb bb GG gg Gg

17. If a chocolate lab is dominant over a yellow lab, give the possible genotypes for the following

18. Traits in Humans Traits Dominant Recessive Phenotype
Possible Genotypes
Earlobes
Free
Attached
Hairline
Widow’s peak
Straight line
Eye shape
Almond
Round
Eyelash length
Long
Short
Tongue dexterity
Can roll
Unable to roll
Thumb
Hitchhikers
Straight
Lip thickness
Thick
Thin
Hair texture
Curly/wavy
Inter-eye distance
Close/medium
Far apart
Lip protrusion
Protruding/slightly
Not protruding
Hand crossing
Left over right
Right over left

19. Rate of Frequency Observed Traits Number observed
Percentage of population
Tongue roller/nonrollers
Free earlobes/attached
Hitchhikers thumb/regular
Widow’s peak/straight
Almond eyes/round
Long lashes/short
Thick lips/thin lips
Curly/straight
Close eyes/far ears
Protruding/not protruding
Left over right/ right over left l