Name:_____________________
My quiz is on:_____________
Mendel, Heredity and Human Genetics Review
Vocabulary: please define the following terms on a separate piece of paper to receive
full credit.
Genetics
Heterozygous
Allele
Multiple Alleles
Genotype
Homozygous
Gene
Carrier
Phenotype
Heredity
Hybrid
Traits
Dominant Allele
Recessive Allele
Codominant Traits
Concepts

What did Mendel say about the following?
o Alleles
o Dominant v. Recessive
o Homozygous v. Heterozygous
o Gametes separating during meiosis

What is a punnett square, and for what is it used?

What is the difference between genotype and phenotype? How are they related?
How are they different?

What is meant when we say a genotype ratio and phenotype ratio?
1
Mendelian Genetics
Try to answer these questions about the following possible genetic crosses:
T = tall
t = short
Y = yellow
y = green
I = inflated
i = wrinkled
1.
Tt x Tt
Genotype Ratio: ___________
Phenotype Ratio: ___________
2.
Cross a homozygous yellow plant with a green plant.
Genotype Ratio: ___________
Phenotype Ratio: ___________
3. Can two plants that are heterozygous for having inflated pods create a plant with
wrinkled pods? Explain. (use a punnett square)
Multiple Alleles
In blood typing, the gene for type A and the gene for type B are codominant. The gene
for type O is recessive. Using the Punnett squares, determine the possible blood types
of the offspring.
o Remember:
Blood Type
Genotypes
A
I AI A, I Ai
B
IBIB, IBi
AB
I AI B
O
ii
1.
Father is type O and mother is type AB.
2
_____%O
_____%A
_____%B
_____%AB
2.
Father is type A heterozygous and mother is type B heterozygous.
_____%O
_____%A
_____%B
_____%AB
3.
Can a man who is type A and a woman who is type AB have a child who is type O?
Do the punnett square to support your answer.
Codominance
In chickens, feather color is codominant. B = black feathers and W = white feathers.
Chickens who are heterozygous for the trait are black and white speckled.
1.
Cross a black chicken (BB) with a speckled chicken (BW).
Genotype Ratio: ___________
Phenotype Ratio: ___________
2.
Cross a white chicken and a black chicken.
Genotype Ratio: ___________
Phenotype Ratio: ___________
3
Sex linked traits
1.
Hemophilia is a sex-linked trait. A woman who is heterozygous for hemophilia
marries a normal man. What will be the possible genotypic and phenotypic ratios
of their offspring?
2.
A phenotypically normal woman has phenotypically normal parents. However, she
has hemophiliac brother.
a)
What are the chances of her being a carrier for hemophilia?
b)
If she is a carrier and marries a normal male, what is the chance of child
with hemophilia?
Incomplete Dominance
1. Snap dragons exhibit incomplete dominance. Two red alleles (RR) results in a red
flower, two white alleles (rr) results in a white flower, and one of each allele (Rr)
results in a pink flower. Predict the outcome (genotype and phenotype) of crossing
two pink flowers.
Pedigrees
1. Based on the pedigree for a recessive
disorder, what is the genotype of individual 3
in generation 2?
4