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For the following questions, write the GENEOTYPES OF THE PARENTS ONLY. DO NOT DO THE PUNNETT SQUARE!
1) A homozygous black rat is crossed with a homozygous white rat (black is recessive).
2) A homozygous brown mouse is crossed with a heterozygous brown mouse (tan is recessive).
3) Two heterozygous white rabbits are crossed.
4) A heterozygous white rabbit is crossed with a homozygous black rabbit.
For the following, complete the punnett square and give the genotype and phenotype PERCENTAGES.
5) A homozygous brown mouse is crossed with a heterozygous brown mouse (tan is the recessive color).
Genotype=
Phenotype=
6) Two heterozygous black rabbits are crossed. Brown fur is recessive.
Genotype=
Phenotype=
7) A heterozygous grey rabbit is crossed with a homozygous black rabbit.
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Genotype=
Phenotype=
Complete a punnett square, list the percentages of each genotypes and each
phenotype.
1. A homozygous red flower is crossed with a homozygous white flower. Red and
white show incomplete dominance.
Genotype=
Phenotype=
2. A heterozygous medium height plant is crossed with a homozygous tall plant. Tall and short show
incomplete dominance.
Genotype=
Phenotype=
3. Two heterozygous grey bunnies are crossed. Black and white fur show incomplete dominance.
Genotype=
Phenotype=
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4. A homozygous red-coated dog is crossed with a homozygous white-coated
dog. Red and white coats are codominant.
Genotype=
Phenotype=
5. Two heterozygous black and white spotted T-rexes are crossed. Black and white are codominant.
Genotype=
Phenotype=
6. A heterozygous black and red dragon is crossed with a homozygous red dragon. Red and black are
codominant.
Genotype=
Phenotype=
7. A nurse at a hospital removed the wrist tags of three babies in the maternity
ward. She needs to figure out which baby belongs to which parents, so she checks
their blood types. Using the chart below, match the baby to its correct parents. Show the crosses to
prove your choices.
Parents
Blood Types
Baby
Blood type
Mr. Hartzel
O
Mrs. Hartzel
A
Jennifer
O
Mr. Simon
AB
Rebecca
A
Mrs. Simon
AB
Holly
B
Mr. Peach
O
Mrs. Peach
O
Hemophilia is a sex-linked trait found on the X chromosome. To get this disease, a person must have a
recessive copy of the gene (h) on every X chromosome. Predict the genotypic and phenotypic
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percentages of the offspring if a woman who was a carrier for the disease had a baby with a man who
had the disease.
Genotype of Mother: _______
Genotype of Father:__________
Genotype=
Phenotype=
Baldness is also a sex-linked trait found on the X chromosome. To become bald, a person must have a
recessive copy of the gene (b) on every X chromosome. Predict the genotypic and phenotypic
probabilities of the offspring if a woman who has no history of baldness in her family (B) had a baby
with a man who was bald.
Genotype of Mother: _______
Genotype=
Genotype of Father:__________
Phenotype=
A woman who is colorblind (XcXc) can expect —
A 100% of her female offspring to be colorblind.
B 100% of her male offspring to be colorblind.
C 50% of her female offspring to be colorblind.
D 50% of her male offspring to be colorblind.
In people, the trait for colorblindness (Xb) is a recessive sex linked trait and normal vision
(XB) is dominant. If a female who is heterozygous for colorblindness has children with a man
who has normal vision, what percent of their male children would be expected to be color
blind?
A 0%
B 25%
C 50%
D 100%
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Imagine that the dark shapes are individual with a recessive disease.
1. Using the letter r, what would the genotype of someone with the disease have to be?
On the diagram above, label all of the dark shapes with that genotype.
2. Using the letter R, what are the two genotypes someone with a white shape could have?
3. Label the genotypes of individuals I1 ,II2 and II3. Remember that if someone has the disease, they had
to get a recessive gene from both parents and that a parent with the disease has to pass on the
recessive gene.
1. If you look at the offspring of the second line, you will notice that one of their kids is black. You can
use this to tell if black is dominant or recessive. Using R/r, what is the genotype of black shapes?
Label all of the black shapes in the diagram.
2. Now go back and label the genotypes of the parents in the second line.
3. Look at the middle parents in the third line and label their genotypes. How do you know their
genotypes? Explain in two sentences below.
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On the question below, make sure you look for parents of the same color that produce a child that is
an opposite color and label that child as being recessive before answering the question.
Since the polled allele is
dominant, the horned allele
has to be recessive. Write in
the genotype of the
recessive individuals BEFORE
you do the problem. Use
N/n
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