Download Genetic Crosses that Involve 2 Traits-

Genetic Crosses that Involve 2 Traits--Complex Problems
In llamas, floppy ears are dominant to pointy ears.Ý Also in llamas, bowlegs
are recessive.
1. Develop a "key"Ý showing the letters for the two traits. (Each trait should
have a different letter). Show the phenotypes of your letters too. Ex: FF =
floppy ears. LL = normal legs
2. A llama with floppy ears (Ff) and bowlegs is crossed with one that is
heterozygous for both traits. Show the genotypes of these two parents
3. Draw a punnet square showing the resulting offspring
4. Show the ratios of the resulting phenotypes, use fractions.
5. A llama that has pointy ears and bowlegs is crossed with one that is
homozygous dominant for both traits. Show the genotypes of the parents.
6. Draw a punnet square showing the resulting offspring
7. Show the ratios of the resulting phenotypes, use fractions
8. A llama that is heterozygous for both traits is crossed with another llama
that is heterozygous for both traits. Show the genotypes of the two parents.
9. Draw a punnet square showing the resulting offspring.
10. Show the ratios of the resulting phenotypes, use fractions.
Oompah Loompa Genetics
Mendelian Genetics and Codominance
SHOW ALL WORK and PUNNET SQUARES
1. Oompahs generally have blue faces which is caused by a
dominant gene. The recessive condition results in an orange
face. Develop a "key" to show the genotypes and phenotypes
possible for Oompa Loompas.
2. Two heterozygous OOmpahs are crossed. What proportion
of the offspring will have orange faces.
3. A blue faced Oompah (homozygous) is married to an orange
faced Oompah. They have 8 children. How many children will
have blue faces?
4. Otis Oompah has an orange face and is married to Ona
Oompah who has a blue face. They have 60 children, 31 of
them have orange faces. What are the genotypes of the
parents.
5. Odie Oompah has a blue face. In fact, everyone in Odie's
family has a blue face, and the family boasts that it is a
"pure" line. Much to his family's horror, he married Ondi
Oompah who "gasp" has an orange face. What are the
gentoypes of their children. Is Odie's line still "pure"?
6. Ona Oompah (from#4) divorces Otis and marries Otto.
Otto has an orange face. What is the probability that Ona
and Otto's children will have orange faces?
7. Oompahs can have red, blue or purple hair. Purple hair
results from the heterozygous condition. Make a "key"
showing the genotypes and phenotypes for hair color. Is this
an example of codominance or incomplete dominance?
8. Orville Oompah has purple hair and is married to Opal
Oompah who brags that she has the bluest hair in the valley.
How many of Opal's children will be able to brag about their
blue hair also?
9. One of Opal's children is born with shocking red hair. Is
Orville the father of this child (show the square to prove
your answer)? But wait, Opal swears she has been faithful
and claims that the hospital goofed and got her baby mixed
with another. Is this a plausible explanation. Show the square
to prove your answer.
10. Olga Oompah has red hair and marries Oliver Oompah who
has blue hair. They have 32 children. What color is their
children's hair?
11. Olivia Oompah is married to Odo Oompah and they both
have purple hair. What color hair and in what proportion
would you expect their children to have?
12. In the land of Oompah, blue hair is highly valued, blue
haired Oompahs even get special benefits. Oscar Oompah has
purple hair but he wants to find a wife that will give him blue
haired children. What color hair should his wife have? What
would be his second choice?
Practice: Codominance and Incomplete Dominance
1. Practice setting up keys for the phenotypes listed in each set. Remember that the
"medium" trait must always be heterozygous.
a) Birds can be blue, white, or white with blue-tipped feathers.
b) Flowers can be white, pink, or red.
c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked.
d) A Sneech can be tall, medium, or short.
e) A Bleexo can be spotted, black, or white.
2. Now, can you figure out in the above list, which of the letters represent codominant
traits and which are incomplete.
Codominant _____________ Incompletely Dominant ________________
3. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the
genotypes for the pictured phenotypes
4. Show the cross between a star-eyed and a circle eyed.
What are the phenotypes of the offspring? ____________
What are the genotypes? __________
5. Show the cross between a circle-star eyed, and a circle eyed.
How many of the offspring are circle-eyed? ____________
How many of the offspring are circle-star eyed? ____________
6. Show the cross between two circle-star eyed.
How many of the offspring are circle-eyed? ____________
How many of the offspring are circle-star eyed? ____________
How many are star eyed? ____________
Genetics: X Linked Genes
In fruit flies, eye color is a sex linked trait. Red is dominant to white.
1. What are the sexes and eye colors of flies with the following genotypes:
XRXr
_________________
XRY
_________________
XRXR
_________________
XrY
_________________
2. What are the genotypes of these flies:
white eyed, male ____________
red eyed female (heterozygous) ________
white eyed, female ___________
red eyed, male ___________
3. Show the cross of a white eyed female X r
X r with a red-eyed male X R Y
4. Show a cross between a pure red eyed female and a white eyed male.
What are the genotypes of the parents:
___________& _______________
.
How many are:
white eyed, male___
white eyed, female ___
red eyed, male ____
red eyed, female ____
5. Show the cross of a red eyed female (heterozygous) and a red eyed male. What are the
genotypes of the parents?
___________ & ________________
How many are:
white eyed, male___
white eyed, female ___
red eyed, male ____
red eyed, female ____
Math: What if in the above cross,
100 males were produced and 200
females.
How many total red-eyed flies
would there be?
____________
6. In humans, hemophilia is a sex linked trait. Females can be normal, carriers, or have the
disease. Males will either have the disease or not (but they won’t ever be carriers)
= female, normal
= male, normal
= female, carrier
= male, hemophiliac
= female, hemophiliac
Show the cross of a man who has hemophilia with a woman who is a carrier.
What is the probability that their children will have the disease? __________
7. A woman who is a carrier marries a normal man. Show the cross. What is the
probability that their children will have hemophilia? What sex will a child in the
family with hemophilia be?
8. A woman who has hemophilia marries a normal man. How many of their children will have
hemophilia, and what is their sex?
9. In cats, the gene for calico (multicolored) cats is codominant. Females that receive a B and
an R gene have black and oRange splotches on white coats. Males can only be black or
orange, but never calico.
B
R
Here’s what a calico female’s genotype would look like.
X
X
Show the cross of a female calico cat with a black male?
What percentage of the kittens will be black and male? _________
What percentage of the kittens will be calico and male? _________
What percentage of the kittens will be calico and female? _________
10. Show the cross of a female black cat, with a male orange cat.
What percentage of the kittens will be calico and female? _____
What color will all the male cats be? ______