Transcript Teacher quality grant - Gulf Coast State College


Dear teacher this was adapted from a
presentation by:
 Nancy
Dow
 Jill Hansen
 Tammy Stundon
Who teach in Bay County
 The missing words have been noted for each
slide in the “Click to add notes” space at the
bottom of each slide.

FLORIDA NEXT GENERATION
SUNSHINE STATE STANDARDS
BENCHMARK
•
SC.912.L.16.1* Use Mendel's laws of segregation and
independent assortment to analyze patterns of inheritance.
(HIGH)
•
SC.912.L.16.2* Discuss observed inheritance patterns caused by
various modes of inheritance, including dominant & recessive
which are simple inheritance & codominant, sex-linked, polygenic,
and multiple alleles (complex inheritance). (HIGH)
Karyotype
-display of pairs of chromosomes
For Humans: 23 homologous
pairs; one chromosome form
mom and the other from dad
Autosomes are chromosomes 1-22
Chromosome pair 23 is your sex
chromosomes
GENETICS
 Gene
- a section of DNA that codes for a
________
 Allele – Any form of a specific gene. You get ____
from each parent.
Dominant Allele - ______case letter
 Recessive Allele - ______case letter

GENETICS
 Karyotype
- the display of the pair of
chromosomes with highlighted alleles
 Phenotype - the physical _________ of the
alleles
 Genotype - allele __________ for a gene of an
individual Bb, BB, or bb (B is the dominant
allele, b is the recessive allele)
 Trait - term for distinguishing phenotypic
features or ______________
INHERITANCE OF GENES
Maternal
chromosome pair
Paternal
chromosome pair
Gene
Maternal gamete: egg
Paternal gamete: sperm
Humans have 23
pairs of
chromosomes (46
individual
chromosomes)
and, thus, two
copies of each
gene.
Each human gamete
has just one copy
of each chromosome
and, thus, one copy
of each gene.
Gametes unite during fertilization.
Child inherits one set of
chromosomes from each
parent and, thus, two
copies of each gene.
ALLELES
What traits will be expressed?
For simple inheritance, you only need _____Dominant allele
for the Dominant trait to be expressed.
Naturally, the only way for a Recessive trait to be expressed is
if the person has ______
Recessive alleles.
Exceptions   
GENETICS
MORE VOCABULARY
 Heterozygous
- a __________ and a
_________ allele (Bb) (also called hybrid)
 Homozygous dominant - ____ dominant
alleles (BB) (also called Purebred)
 Homozygous recessive - ____ recessive
alleles (bb) (also called Purebred)
 Only one dominant allele need to be
present to be expressed
PUNNETT SQUARES ILLUSTRATE GENETIC CROSSES.

The Punnett square is a grid system for
predicting all __________ genotypes resulting
from a cross.


The axes represent
the possible _________
of each parent.
The boxes show the
possible _________
of the offspring.
• The Punnett square yields
the ratio of possible
___________and
____________.
A MONOHYBRID CROSS INVOLVES ONE TRAIT.

__________ crosses examine the inheritance
of only ____specific trait.
 homozygous
 Genotype:
dominant X homozygous recessive
all heterozygous (100%)
 Phenotype: all dominant (100%)
PUNNETT SQUARE:
A Punnett square is a useful tool for determining the possible
outcomesALBINISM
of a cross between two individuals.
MOTHER
albino
homozygous
aa
Cross 1 (F 1)
a
FATHER
pigmented
homozygous
AA
GAMETES
a
GAMETES
A
Aa
Aa
Aa
Aa
A
OFFSPRING Genotype
All heterozygous Aa
Phenotype
All pigmented
– If you cross a heterozygous with a heterozygous (Ff X Ff)
– What is the genotypic ratio of the offspring?
– 1:2:1 homozygous dominant: heterozygous: homozygous
recessive; (25%:50%:25%)
– What is the phenotypic ratio of the offspring?
– 3:1 dominant: recessive (75%:25%)
MOTHER
pigmented
heterozygous
Aa
Cross 2
(F2)
A
FATHER
pigmented
heterozygous
Aa
GAMETES
a
Your
genotype
and
phenotype
results are
presented
separately
GAMETES
A
AA
Aa
Aa
aa
a
OFFSPRING
Genotype
Phenotype
1/4 homozygous dominant AA
2/4 heterozygous Aa
1/4 homozygous recessive aa
3/4 pigmented
1/4 albino
3:1
RATIO
• If you cross a heterozygous with homozygous recessive
(Ff X ff)
• What is the genotypic ratio?
• 1:1 heterozygous: homozygous recessive
• What is the phenotypic ratio?
• 1:1 dominant: recessive
•
A ___________is a cross between an
organism with an unknown genotype and an
organism with the recessive phenotype
Why use the
recessive
phenotype to
test an
unknown?
HEREDITY PATTERNS CAN BE CALCULATED WITH
PROBABILITY.


____________is the likelihood that something will happen.
Probability predicts an average number of occurrences, not an
exact number of occurrences.
number of ways a specific event can occur
• Probability =
number of total possible outcomes
• Probability applies to
_________ events such
as meiosis and
fertilization.
GENETICS AND PROBABILITY
IF…
The mother is albino, and
the father is heterozygous
aa
Aa
100%
a
50%
a
1.0
A
×
THEN…
There is a 100% chance that
the mother’s egg will carry the
recessive a allele and a 50%
chance that a sperm will carry
the recessive a allele
a
0.5
Multiply the two components
together
to determine the overall probability.
AND…
= 0.5 or 50%
chance the
offspring will
be albino.
aa
A DIHYBRID CROSS INVOLVES _____TRAITS.

Mendel’s dihybrid crosses with heterozygous
plants yielded a 9:3:3:1 phenotypic ratio.
• Mendel’s dihybrid crosses
led to his second law,
the
______________________
_______________.
• The law of independent
assortment states that
allele pairs separate
independently of each other
during meiosis.
Dihybrid Cross:
a cross that shows the possible offspring
for two traits
Fur Color:
B: Black
b: White
Coat Texture:
R: Rough
r: Smooth
In this example, we will cross a
heterozygous individual with another
heterozygous individual. Their
genotypes will be:
BbRr x BbRr
DIHYBRID CROSSES:
A CROSS THAT SHOWS THE POSSIBLE OFFSPRING FOR TWO
TRAITS
BbRr x BbRr
BR
Fur Color:
B: Black
b: White
BR
Coat Texture:
R: Rough
r: Smooth
Br
Then, find the
possible
genotypes of
the offspring
bR
br
Br
bR
br
DIHYBRID CROSSES:
A CROSS THAT SHOWS THE POSSIBLE OFFSPRING
FOR TWO TRAITS
BR
Br
bR
br
BR
BBRR
BBRr
BbRR
BbRr
Br
BBRr
BBrr
BbRr
Bbrr
bR
BbRR
BbRr
bbRR
bbRr
br
BbRr
Bbrr
bbRr
bbrr
BbRr x BbRr
Fur Color:
B: Black
b: White
Coat Texture:
R: Rough
r: Smooth
How many of the offspring
would have a black, rough
coat?
BR
Br
bR
br
BR BBRR
BBRr
BbRR
BbRr
BBRr
BBrr
BbRr
Bbrr
How many of the offspring
would have a white, rough bR
coat?
BbRR
BbRr
bbRR
bbRr
br
BbRr
Bbrr
bbRr
bbrr
How many of the offspring
would have a black,
Br
smooth coat?
How many of the offspring
would have a white,
smooth coat?
Fur Color:
Coat Texture:
B: Black
R: Rough
b: White
r: Smooth
ADAPTED FROM A PRESENTATION BY:
Nancy Dow
 Jill Hansen
 Tammy Stundon
