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

GeneticsHistory

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 1st number is 5?

2nd number is 2?

3rd number is 6?

4th number is 5?

5th number is 1?

6th number is 3?

16

16

16

16

16

16

X X X X X

146,65

6

= .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

male female

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

male female

F1 GenerationF2 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:


– Homozygous Recessive: combination of 2 recessive alleles

allele

pp

Homozygous recessive

Gene for recessive white flowers





– Heterozygous: Combination of 1 dominant, 1 recessive allele

allele

pP

Heterozygous



PP

pp

Pp




– Heterozygous: Combination of 1 dominant, 1 recessive allele

• Phenotype: Physical expression of the gene

Phenotype:

Phenotype:

PURPLE

white

30 Seconds: Discuss with your neighbor:

Choices:1) YY2) Tall3) Yy4) SS5) yY6) gg7) Smooth8) Green9) TT10)Dwarf

Which choice(s) are examples genotypes?



Which choice(s) are examples heterozygous genotypes?



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 ppP

Pp

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, 2Pp, 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 = healthyh = disease

H HH hh h

healthy Healthy (carrier)

disease

Hh 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%

Review1) 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?

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

Documents

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