Hobbie 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.
C) If correct, you will win a prize.
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?
How do you calculate
th
4 number is 5?
the overall odds?
th
5 number is 1?
6th number is 3?
1
6
X
1
6
1
1
1
X
X
X
6
6
6
1
= .00002%
46,656
X
1
6
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
female
F1 Generation
• P Generation:
– Male: purple
flowers
– Female: Purple
flowers
• F1 Generation:
– 100% purple
• Learned? Traits
are inherited from
parents
• P Generation:
P Generation
male
female
– Male: white
flowers
– Female: white
flowers
F1 Generation
• F1 Generation:
– 100% white
P Generation
male
female
• P Generation:
– Male: purple
flowers
– Female: White
flowers
• F1 Generation:
F1 Generation
– 100% purple
• Learned?
– Some traits are
dominant
– Some traits are
recessive
• F1 Generation:
– Male: purple flowers
– Female: Purple
flowers
male
female
Remember… these had a white parent
F2
F1 Generation
Generation
• F2 Generation:
– 75% purple
– 25% white
• Learned?
– Offspring won’t always
resemble the parents
– Traits can skip
generations
Mendel’s 7
traits studied
Each trait had a 3:1
ratio. No way that
can be a
coincidence!
Gene for dominant
purple flowers
Gene for dominant
purple flowers
• Genotype: combination
of two alleles
– Homozygous Dominant:
combination of 2
dominant alleles
P
Homozygous
dominant
allele
P
Gene for recessive
white flowers
Gene for recessive
white flowers
p
Homozygous
recessive
allele
p
• Genotype: combination
of two alleles
– Homozygous Dominant:
combination of 2
dominant alleles
– Homozygous Recessive:
combination of 2
recessive alleles
Gene for dominant
purple flowers
Gene for recessive
white flowers
p
P
Heterozygous
allele
• 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
• Genotype: combination
of two alleles
PP
Phenotype:
PURPLE
Pp
pp
Phenotype:
white
– 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
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?
Homozygous
dominant
Homozygous
recessive
PP
pp
Pp
Pp
Pp
Pp
• 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? 100%
1 minute: Cross a heterozygous purple (Pp) plant with
another heterozygous purple (Pp) plant
1) List the genotypes.
1 PP, 2Pp, 1pp
2) List the phenotypes.
3 purple, 1 white
3) What is the
probability of having a
white plant?
25%
Autosomal Recessive Inheritance
Hh
• 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
alleles to have the
disease
H
H
h
healthy
Hh
Hh
h
Healthy (carrier)
H = healthy
h = disease
disease
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
50%
healthy child? _________
2) Probability of having a homozygous
0%
dominant child? ________
review
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) 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?