Kobe Lottery Directions: I am going to roll 6 dice…one at a time. If you guess the 6 numbers in order, you will win a prize.

“Father of Genetics” Famous for pea plant studies Mendel studied seven pea plant traits Results shaped our understanding of genetics

What is Genetics? Genetics: Study of heredity Heredity: passing of traits from parent to child Patterns of relatedness can help predict offspring characteristics

Mendel’s 7 traits studied

Pure Breeding Purple & White Flowers Parent Generation (P) Mendel crossed a purple flower with a white flower. Result: 100% offspring were purple (even though one parent was white) 1 st Generation (F1) Mendel crossed 2 F1 purple flowers. Result: 75% purple flowers, 25% white flower (3:1 ratio)

Each trait had a 3:1 ratio. No way that can be a coincidence!

1 gene may prevent the expression of another Organisms inherit 2 copies of each gene –One from each parent

Genes are pieces of DNA that create proteins: –located on chromosomes –inherited from parents –come in dominant & recessive forms (alleles) –Ex: Flower color Purple allele (dominant) White (recessive) Letters used to abbreviate alleles –Dominant Allele = Capital letter –Recessive Allele = Lowercase letter

Defined: Genetic makeup of an organism Homozygous dominant: combination of two dominant alleles (PP) Heterozygous: combination of one dominant, one recessive allele (Pp) Homozygous recessive: combination of two recessive alleles (pp)

Defined: Physical appearance of a gene Example: What’s the phenotype of a flower that is PP genotype? __________ What’s the phenotype of a flower with Pp genotype? ___________ What’s the phenotype of a flower with a pp genotype? __________ Purple White

Genetics Vocabulary Review Choices: 1)YY 2)Tall 3)Yy 4)SS 5)yY 6)gg 7)Smooth 8)Green 9)TT 10)Dwarf Which choice(s) are examples of: Genotypes? 1, 3, 4, 5, 6, 9 Phenotypes? 2, 7, 8, 10 Homozygous genotypes? 1, 4, 6, 9 Heterozygous genotypes? 3, 5 Homozygous recessive genotypes? 6 Homozygous dominant genotypes? 1, 4, 9

Cross a homozygous dominant yellow (YY) plant with a homozygous recessive green (yy) plant Key Y = yellow y = green Probability of growing a yellow plant? _____________ Probability of growing a homozygous recessive plant? ____________ 100% 0% Probability of growing a homozygous dominant plant? ____________ 0%

Cross a heterozygous dominant yellow (Yy) plant with a heterozygous dominant yellow (Yy) plant Key Y = Yellow y = green Probability of growing a heterozygous plant? ________ Probability of growing a green plant? ________ Probability of growing pure yellow? _________ 50% 25% 25%

Kobe Kuiz 1) How are dominant alleles expressed? Recessive? 2) Which of the following are genotypes? Phenotypes? TT Green yY Pp Purple gg Smooth 3) Which of the following are heterozygous genotypes? TT Green yY Pp Purple gg Smooth 4) Genes may often be found in two forms (dominant and recessive). What are these alternate forms of a gene called? 5) Genes are segments of DNA found on _______________. 6) If item A is found in a 2:1 ratio compared to item B, what percentage is item A? 7) If item A is found in a 4:1 ratio compared to item B, what percentage is item A? 8) Cross a heterozygous tall with a homozygous recessive short pea plant. List the genotypes in a Punnett square. What’s the probability of growing a tall plant? What’s the probability of growing a homozygous dominant plant? What’s the probability of growing a homozygous recessive plant?