Download 2 - Pedigrees - practice questions

PEDIGREES: Interpreting “genetic” information from Diagrams
Name: ________________
IWBAT analyze pedigree for genotypic and phenotypic information, as well as information about patterns of inheritance, and
IWBAT create a pedigree.
Pedigrees are used to show transmission of a specific trait or disorder throughout a family. Pedigrees can give us
information about the principle of inheritance (dominant, recessive).
How do pedigrees work: Basic Questions:
1- How are all males represented?
____________________
2- How are all of the females represented?
___________________
3- Who is the youngest individual on this pedigree?
a. a
c. c
b. b
d. d
4- Which of the following is not true about “b”: He is…?
a. The father of individual “c”
b. The Grandfather of “d”
c. The brother of “a”
d. Not affected with lung disease
5- Who is affected with lung disease?
a. All of b’s daughters
b. All of c’s children
c. one of d’s brother’s
d. all of a’s children
A great genetic detective would ask the following questions and complete the following detective work when
looking at a pedigree:
1. Look for a set of parents who have the same phenotype (both affected or both not affected), and
then look at their offspring to see if they are all the same or different.
! If children are different from the parents, then the parents have to be ___________.
! If the parents that you are looking at are affected (darkened), then the disorder for the
pedigree is also ________________________.
! If the parents that you are looking at are NOT affected, then the disorder for the pedigree
would be _____________________.
*This will always be your strongest evidence, and therefore, you should always start by looking for this
information.
2) Determine the genotypes in the pedigrees to confirm your answers (a great geneticist would create
punnett squares to confirm their predictions).
Questions that require use of data and knowledge of genetics to answer:
6- One can most reasonably deduce from the
information in the pedigree that this trait is:
a. Dominant
b. Recessive
7- What accounts for the fact that none of a’s
children were affected with lung disease?
a. The father must be heterozygous
dominant
b. The father must be homozygous
dominant
c. The father must be homozygous
recessive
d. The mother is unable to pass her alleles
to her offspring
8- The offspring of “a” and his wife most reasonably have what genotype?
a. Heterozygous dominant
c. Homozygous recessive
b. Homozgyous dominant
d. Cannot be determined
9- What accounts for the fact that some of b’s children are affected with lung disease?
a. “b” is homozygous dominant and his wife is homozygous recessive
b. “b” is homozygous recessive and his wife is homozygous dominant
c. “b” is heterozygous dominant and his wife is homozygous recessive
d. “b” is heterozygous dominant and his wife is homozygous dominant
10- Based on the data of the offspring, parents, and siblings of “c” and her husband, it can be
reasonably assumed that they have the following genotypes:
a. They both are homozygous recessive
b. They both are homozygous dominant
c. They are both heterozygous dominant
d. They are both dominant, but we cannot determine if they are heterozygous or homozygous
11- What is the genotype of “d”?
a. Heterozygous dominant
b. Homozygous dominant
c. Heterozygous dominant or Homozygous dominant (not enough information to tell)
d. Homozygous recessive
12- If “a” were to mate with the wife of “b”, and they had 4 children, we could most reasonably
assume that their children would:
a. All be affected with lung disease
b. 50% of the children would be affected with lung disease
c. Only the daughters would be affected with lung disease
d. No one would be affected with lung disease
Graph Genetic Information by Making a Pedigree:
Sketch a pedigree that shows the following information for an unknown disorder in the blank space below/
or on your whiteboard/ separate piece of paper).
Family Member
A1-Grandfather
A2-Grandmother
B1-Son 1
B2-Son 2
B3-Daughter 2
B4-Husband of Daughter 2
C1-Son 1 (of B3 & B4)
C2- Daughter 1 (of B3 & B4)
C3- Son 2 (of B3 & B4)
Affected or not
Affected
Not
Not
Affected
Not
Not
Not
Affected
Not
Tips for making your own pedigrees:
1)
2)
3)
4)
5)
Remember to make males as SQUARES and
females as CIRCLES.
Remember to shade/ darken any individual who
is affected.
A horizontal line between a circle and square
indicates to individuals who are mating.
A vertical line coming down from these parents
connects them to their children (if more than
one, form a horizontal line to connect them all)
Look at example pedigrees for structure
1. Based on the information provided, this pedigree shows a trait that is most likely:
a. Dominant
b. Recessive
2. Identify the genotypes for the following individuals:
A1- ___________________
B2- ___________________
C2- ___________________
B1- ___________________
B4- ___________________
C3- ___________________
Below is a pedigree for a different lung disease .
1. Based on the information above, it is most
likely that this lung disease is:
a. Dominant
b. Recessive
2.
Determine the genotypes for each
individual marked a-e:
a.
_______
d. _________
b.
_______
e. _________
c.
_______
3.
Is there any possibility that “c” and her
husband could have a child affected with the
disorder? Explain.
4.
Could “e” and her husband have any children
not affected with the disorder? Explain.
Below is a pedigree for an inherited heart disease.
a
1.
Based on the information above, it is most
likely that this heart disease is:
a. Dominant
b. Recessive
2.
What is the probability that “F’ will be
affected with heart disease? _____________
3.
What is the genotype of “a”?
____________________
4.
What is the genotype of “b”?
____________________
5.
What is the genotype of “c”?
_______________________
6.
What is the genotype of
“d”?_______________________
b
c
d
e
7.
What is the genotype of “e”? __________________________________
8.
Could “c” and “d” have a child affected with heart disorder? Why/ why not?