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)

1st 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

Purple

White

Genetics Vocabulary ReviewChoices:

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 Kuiz1) How are dominant alleles expressed? Recessive?2) Which of the following are genotypes? Phenotypes?

TT Green yY Pp Purple gg Smooth3) Which of the following are heterozygous genotypes?

TT Green yY Pp Purple gg Smooth4) 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?