Date post: | 13-Dec-2015 |
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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
• 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
• 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
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
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
pP
Heterozygous
Gene for dominant purple flowers
Gene for recessive white flowers
PP
pp
Pp
• 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:
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?
30 Seconds: Discuss with your neighbor:
Choices:1) YY2) Tall3) Yy4) SS5) yY6) gg7) Smooth8) Green9) TT10)Dwarf
Which choice(s) are examples heterozygous genotypes?
30 Seconds: Discuss with your neighbor:
Choices:1) YY2) Tall3) Yy4) SS5) yY6) gg7) Smooth8) Green9) TT10)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 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?