1.
In seals, the gene for the length of the whiskers has two alleles. Long
whiskers are
dominant,
short whiskers are recessive. We use the letter “w” to describe whisker length.
a.
Write the homozygous dominant genotype.
__________
b.
What is the phenotype for
the genotype above (#a)? ___________
c.
Write the heterozygous genotype.
______
d.
What is the phenotype for
the genotype above (#c)?________________
e.
Write the homozygous recessive genotype.________
f.
What is the phenotype for
the genotype above (#e)?________________
g.
In a cross between a homozygous dominant papa seal with a homozygous recessive
mama seal, what
percentage
of the offspring would be expected to have long whiskers?
Punnett Square:%
with long whiskers?
h.
In a cross of two heterozygous parent seals, what percentage of the offspring would
be expected to have short whiskers?
Punnet
Square: %
with short whiskers?
2.
In purple people eaters, one-horn is dominant and no horns
are recessive. A homozygous dominant purple people eater mates with a no-horned
purple people eater.Use H and h for alleles.
a.
What are the genotype probabilities of the offspring? ________________
b.
What are the phenotype probabilities of the offspring? _______________
3.
In Gateway gators, blue is the dominant skin color (B), red is recessive (b).
But a cross between a blue gator & a red gator produces a purple gator (Bb).
a.
What pattern of inheritance does this
illustrate? ____________________
b.
If a purple gator is crossed with a blue gator, what is the chance the baby
will be red? ___________
Blood Type Problems
1. List all the possible genotypes for each of the 4 blood
types (UseIA, IB, and i):
Type O ____________Type
B______________
Type A ____________Type
AB_____________
SHOW WORK FOR PROBLEMS BELOW!
2. A man with AB blood is married to a woman with AB blood.
What blood types will their children be and in what proportion?
3. A man who has type B blood (genotype: BB) is married to a woman with type O
blood. What blood type will their children have?
4. A woman with type A blood (genotype: AO) is married to a type B person
(genotype: BO). What blood types will their children have?
5. A woman with type A blood is claiming that a man with type AB blood is the
father of her child, who is also type AB. Could this man be the father? Show the
possible crosses; remember the woman can have AO or AA genotypes.
6. A man with type AB blood is married to a woman with type
O blood. They have two natural children, and one adopted child. The children's
blood types are: A, B, and O. Which child was adopted?
7. A person with type O blood is married to a person with type A blood (unknown
genotype). They have 6 children, 3 of them have type A blood, three of them
have type O blood. What is the genotype of the two parents?
Pedigree Problems
1.
Huntington’s disease is a dominant disease. Individuals who are homozygous
dominant and heterozygous get the disease, but individuals who are homozygous
recessive do not get the disease.
a.
What are the genotypes of people who get Huntington’s disease? _________________________
b.
Both parents are heterozygous for the Huntington’s
allele. What is the chance that their child will not have Huntington’s
disease? _______________________________
2.Which people are affected?
What
shape represents a male?
What
shape represents a female?
How
do you know if people are married?
How
do you know if people are siblings?
3.Is the allele for widow’s peal dominant or
recessive?
Make
a punnett square for the 4th generation (hint: if the 3rd
generation has a baby)
4.What is the genotype of the affected people?
Why
is there a “?” for some of the people?
Which
generation has 2 affected siblings?
Is
there any explanation for the higher frequency of affected people in this
generation (from above)?
Karyotype Problems
A chart of chromosome
pairs is called a karyotype.This is collected from a sample of cells from
an individual or fetus.Metaphase
chromosomes are photographed, and the chromosome pictures are enlarged, cut
apart and arranged in pairs on a chart according to length and location of the
centromere.
How many pairs of chromosomes do humans
have?
Is
this person male or female?How can
you tell?
The
sex of an individual is determined by what?The number of X chromosomes or Y
chromosomes?
Examine
the pedigree, what is wrong with karyotype?What location is the disorder?
This
is called Trisomy 21 or Down Syndrome.What is this disorder?
