Tuesday, December 13, 2011
Name: ____________________________________ Period: ____
Describe heredity as the passage of instructions from one generation
Competency
to another and recognize that heredity information is contained in
3d – DOK 2
genes, located in the chromosomes of each cell.
8th Grade –
I can use information from pedigrees to predict future offspring.
Lesson 5.8
Page
8
Unit 5 – Heredity and Genetics: Predicting Offspring from Pedigrees
Quick Review
1. In a graph, the independent variable is shown on the x-axis and the dependent
variable is shown on the y-axis.
2. In a velocity v. time graph, velocity is the dependent variable and time is the
independent variable.
Use the four graphs to the right to answer the questions below.
3. Graph that has an
acceleration of zero = C
4. Graph with a positive
acceleration = B
5. Graph with a negative
acceleration = A
6. Graph with a non-constant
acceleration = D
Key Points on Predicting Offspring from Pedigrees
1. Pedigrees are very useful for predicting the genotypes and phenotypes of offspring.
a. Pedigrees CANNOT be used to predict the sex of offspring. There is always a
50% chance that an offspring will be male and a 50% chance that it will be
female.
2. To make a prediction using a pedigree, you must be told the inheritance pattern of the
trait.
a. The two main types of traits are autosomal recessive and autosomal dominant.
i. It if is a recessive trait, the offspring will only have the trait if its genotype is
homozygous recessive
ii. It if is a dominant trait, the offspring will have the trait whenever it has the
dominant allele
3. How
a. Determine the genotypes of the parents.
b. Complete a Punnett square.
c. Determine the possible genotypes of the offspring.
d. Determine the possible phenotypes of the offspring.
4. Shooting For ADVANCED
a. Whether an organism is male or female is determine
by its sex chromosome.
i. Females have two X sex chromosomes (XX)
and males have an X and a Y sex
chromosome (XY).
b. There are two other types of traits, X-linked
dominant and X-linked recessive.
X
X
Y
X
Tuesday, December 13, 2011
Name: ____________________________________ Period: ____
i. These genes are only found on the X chromosome.
c. X-linked recessive
i. Trait is only seen in females if both X chromosomes have the allele.
ii. Trait is seen in males only if mother is a carrier because they always
receive the Y chromosome from their father.
d. X-linked dominant
i. Trait is seen in females if either X chromosome has the allele.
ii. Trait is seen in males only if mother has the mutant allele.
Predicting Offspring from Pedigrees: Guided Practice
In humans, earlobes can be considered attached or unattached. When the bottom portion
of the earlobe is attached directly to head, these are considered attached earlobes. When
the bottom portion of earlobe slopes upward before attaching to head these are
unattached earlobes. Unattached earlobes (E) are dominant to attached earlobes (e). Use
this information to answer the questions below.
1. How many people in this family have
unattached earlobes? ________
2. How many males have attached
earlobes? ________
3. If family members 4 and 5 from the
second generation mate, what is the
chance that their offspring will have
unattached earlobes? ________
4. What is the chance that they will be
carriers for the unattached earlobe
allele? ________
Predicting Offspring from Pedigrees: Independent Practice
The pedigree at the right shows the inheritance of Huntington’s Disease, an autosomal
dominant trait, which causes nerve cells to degenerate.
1. How many males are in the pedigree?
2. How many males have Huntington’s?
3. How many females are in the pedigree?
4. How many females have Huntington’s?
5. If family members 3 and 4 from generation two mate,
what is the chance that their children will have
Huntington’s?
6. What must the genotype be for family member 2 in the
second generation?
The pedigree at the right shows the inheritance of color
blindness, an X-linked recessive trait.
7. Show the cross between the parents in the first
generation.
8. Describe the parents of a colorblind female.
Tuesday, December 13, 2011
Name: ____________________________________ Period: ____
Describe heredity as the passage of instructions from one generation
Competency
to another and recognize that heredity information is contained in
3d – DOK 2
genes, located in the chromosomes of each cell.
8th Grade –
I can use information from pedigrees to predict future offspring.
Lesson 5.8
Page
8
Unit 5 – Heredity and Genetics: Predicting Offspring from Pedigrees
Quick Review
1. In a graph, the independent variable is shown on the
variable is shown on the
-axis.
2. In a velocity v. time graph, velocity is the
variable.
Use the four graphs to the right to answer the questions below.
3. Graph that has an
acceleration of zero = ___
4. Graph with a positive
acceleration =
5. Graph with a negative
acceleration =
6. Graph with a non-constant
acceleration =
-axis and the dependent
variable and time is the
Key Points on Predicting Offspring from Pedigrees
1. Pedigrees are very useful for
the
and
of
.
a. Pedigrees
be used to predict the
of offspring. There is
always a
chance that an offspring will be male and a
chance
that it will be female.
2. To make a prediction using a pedigree, you must be told the
of the trait.
a. The two main types of traits are
and
.
i. It if is a recessive trait, the offspring will only have the trait if its genotype is
ii. It if is a dominant trait, the offspring will have the trait whenever it has the
3. How
a. Determine the
of the
.
b. Complete a
.
c. Determine the possible
of the offspring.
d. Determine the possible
of the offspring.
4. Shooting For ADVANCED
a. Whether an organism is male or female is determine by its
i. Females have two
sex chromosomes (
) and males have an
and a
sex chromosome (
).
b. There are two other types of traits,
and i. These genes are only found on the
.
.
Tuesday, December 13, 2011
Name: ____________________________________ Period: ____
c. X-linked recessive
i. Trait is only seen in females if
X chromosomes have the allele.
ii. Trait is seen in males only if mother is a
because males always
receive the
chromosome from their
.
d. X-linked dominant
i. Trait is seen in females if
X chromosome has the allele.
ii. Trait is seen in males only if
has the mutant allele.
Predicting Offspring from Pedigrees: Guided Practice
In humans, earlobes can be considered attached or unattached. When the bottom portion
of the earlobe is attached directly to head, these are considered attached earlobes. When
the bottom portion of earlobe slopes upward before attaching to head these are
unattached earlobes. Unattached earlobes (E) are dominant to attached earlobes (e). Use
this information to answer the questions below.
1. How many people in this family have
unattached earlobes? ________
2. How many males have attached
earlobes? ________
3. If family members 4 and 5 from the
second generation mate, what is the
chance that their offspring will have
unattached earlobes? ________
4. What is the chance that they will be
carriers for the unattached earlobe
allele? ________
Predicting Offspring from Pedigrees: Independent Practice
The pedigree at the right shows the inheritance of Huntington’s Disease, an autosomal
dominant trait, which causes nerve cells to degenerate.
1. How many males are in the pedigree?
2. How many males have Huntington’s?
3. How many females are in the pedigree?
4. How many females have Huntington’s?
5. If family members 3 and 4 from generation two mate,
what is the chance that their children will have
Huntington’s?
6. What must the genotype be for family member 2 in the
second generation?
The pedigree at the right shows the inheritance of color
blindness, an X-linked recessive trait.
7. Show the cross between the parents in the first
generation.
8. Describe the parents of a colorblind female.
Tuesday, December 13, 2011
Name: ____________________________________ Period: ____
Describe heredity as the passage of instructions from one generation
Competency
to another and recognize that heredity information is contained in
3d – DOK 2
genes, located in the chromosomes of each cell.
8th Grade –
I can use information from pedigrees to predict future offspring.
Lesson 5.8
Page
8
Unit 5 – Heredity and Genetics: Predicting Offspring from Pedigrees
Quick Review
1. In a graph, the independent variable is shown on the
variable is shown on the
-axis.
2. In a velocity v. time graph, velocity is the
variable.
Use the four graphs to the right to answer the questions below.
3. Graph that has an
acceleration of zero = ___
4. Graph with a positive
acceleration =
5. Graph with a negative
acceleration =
6. Graph with a non-constant
acceleration =
-axis and the dependent
variable and time is the
Key Points on Predicting Offspring from Pedigrees
1. Pedigrees are very useful for
the
and
of
.
a. Pedigrees
be used to predict the
of offspring. There is
always a
chance that an offspring will be male and a
chance
that it will be female.
2. To make a prediction using a pedigree, you must be told the
of the trait.
a. The two main types of traits are
and
.
i. It if is a recessive trait, the offspring will only have the trait if its genotype is
ii. It if is a dominant trait, the offspring will have the trait whenever it has the
3. How
a. Determine the
of the
.
b. Complete a
.
c. Determine the possible
of the offspring.
d. Determine the possible
of the offspring.
4. Shooting For ADVANCED
a. Whether an organism is male or female is determine by its
i. Females have two
sex chromosomes (
) and males have an
and a
sex chromosome (
).
.
Tuesday, December 13, 2011
Name: ____________________________________ Period: ____
Predicting Offspring from Pedigrees: Guided Practice
In humans, earlobes can be considered attached or unattached. When the bottom portion
of the earlobe is attached directly to head, these are considered attached earlobes. When
the bottom portion of earlobe slopes upward before attaching to head these are
unattached earlobes. Unattached earlobes (E) are dominant to attached earlobes (e). Use
this information to answer the questions below.
1. How many people in this family have
unattached earlobes? ________
2. How many males have attached
earlobes? ________
3. If family members 4 and 5 from the
second generation mate, what is the
chance that their offspring will have
unattached earlobes? ________
4. What is the chance that they will be
carriers for the unattached earlobe
allele? ________
Predicting Offspring from Pedigrees: Independent Practice
Use the pedigree below showing a disease called phenylketonuria (PKU) to answer questions
1 – 4. PKU is an autosomal recessive disorder which
causes mental retardation and seizures.
1. What is the genotype of an individual with PKU?
2. What must the genotype of family member 1 and
2 have been?
3. The condition of family member 12 and 13 is
unknown. Predict their genotype.
4. If family member 5 mates with a homozygous
dominant person, what is the chance their offspring will be a carrier for PKU?
The pedigree at the right shows the inheritance of Huntington’s Disease, an autosomal
dominant trait, which causes nerve cells to degenerate.
5. How many males are in the pedigree?
6. How many males have Huntington’s?
7. How many females are in the pedigree?
8. How many females have Huntington’s?
9. If family members 3 and 4 from generation two
mate, what is the chance that their children will
have Huntington’s?
10. What must the genotype be for family member 2 in the second generation?