The Lottery Directions: A)I am going to roll 6 dice…one at a time. B)In order, write the numbers you think I will roll.

What were the odds of you winning? Pretend these were the numbers you guessed. What are the odds the 1 st number is 5? 2 nd number is 2? 3 rd number is 6? 4 th number is 5? 5 th number is 1? 6 th number is 3? X XXXX 1 46,656 =.00002% How do you calculate the overall odds?

What is Genetics? Genetics: Study of heredity Heredity: passing of traits from parent to child Gregor Mendel –Austrian monk –Uncovered pattern for how traits can be passed from generation to generation

Mendel’s 7 traits studied

P Generation: –Male: purple flowers –Female: Purple flowers F1 Generation: –100% purple Learned? Traits are inherited from parents malefemale P Generation F1 Generation

P Generation: –Male: white flowers –Female: white flowers F1 Generation: –100% white male female P Generation F1 Generation

P Generation: –Male: purple flowers –Female: White flowers F1 Generation: –100% purple Learned? –Some traits are dominant –Some traits are recessive male female P Generation F1 Generation

malefemale F1 Generation F2 Generation F1 Generation: –Male: purple flowers –Female: Purple flowers F2 Generation: –75% purple –25% white Learned? –Offspring won’t always resemble the parents –Traits can skip generations Remember… these had a white parent

Mendel’s 7 traits studied

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

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

Genotype: genetic make-up of an organism (combination of two alleles) –Homozygous Dominant: combination of 2 dominant alleles allele PP Homozygous dominant Gene for dominant purple flowers

Genotype: combination of two alleles –Homozygous Dominant: combination of 2 dominant alleles –Homozygous Recessive: combination of 2 recessive alleles allele pp Homozygous recessive Gene for recessive white flowers

Genotype: combination of two alleles –Homozygous Dominant: combination of 2 dominant alleles –Homozygous Recessive: combination of 2 recessive alleles –Heterozygous: Combination of 1 dominant, 1 recessive allele allele p P Heterozygous Gene for dominant purple flowers Gene for recessive white flowers

PP pp PpPp Genotype: combination of two alleles –Homozygous Dominant: combination of 2 dominant alleles –Homozygous Recessive: combination of 2 recessive alleles –Heterozygous: Combination of 1 dominant, 1 recessive allele Phenotype: Physical expression of the gene Phenotype: PURPLE white

30 Seconds: Discuss with your neighbor: 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 genotypes?

30 Seconds: Discuss with your neighbor: 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 heterozygous genotypes?

30 Seconds: Discuss with your neighbor: 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 phenotypes?

Defined: Genetics tools used to predict offspring probability Setting Up Punnett Squares: 1) Parent genotypes on outside of the squares 2) Simply fill in each square 3) Inside squares represent the possible offspring genotypes Probability of growing purple flowers? P pp P P p P P P p p p 100% Homozygous dominant Homozygous recessive

1 minute: Cross a heterozygous purple (Pp) plant with another heterozygous purple (Pp) plant 1) List the genotypes. 2) List the phenotypes. 3) What is the probability of having a white plant? 1 PP, 2P p, 1pp 3 purple, 1 white 25%

Autosomal Recessive Inheritance Autosome: Non-sex chromosome Autosomal disorders are caused by genes found on the non-sex chromosomes –ex: Sickle cell = chromosome #11 –ex: Cystic fibrosis = chromosome #7 Sufferers must inherit 2 recessive alleles to have the disease H = healthy h = disease H H H h hh healthy Healthy (carrier)disease Hh

1 Minute: Maria is a heterozygous healthy (Hh) female and Jeff suffers from recessive cystic fibrosis (hh). Key H = healthy h = cystic fibrosis 1) Probability of having a healthy child? _________ 2) Probability of having a homozygous dominant child? ________ 50%0%

Review 1) How are dominant alleles expressed? Recessive? 2) Which of the following are genotypes? Phenotypes? Heterozygous genotypes? TT Green yY Pp Purple gg Smooth 3) Genes may often be found in two forms (dominant and recessive). What are these alternate forms of a gene called? 4) Genes are segments of DNA found on _______________. 5) If item A is found in a 2:1 ratio compared to item B, what percentage is item A? 6) If item A is found in a 4:1 ratio compared to item B, what percentage is item A? 7) 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?