Mendelian and Human Genetics Mastery Test Review
Fill in the blank using the options provided below:
different
dihybrid
dominant
Gregor Mendel
heterozygous
homozygous
monohybrid
recessive
same
___________ _________ is said to be the father of genetics due to his early studies on
garden pea plants. Mendel performed two types of crosses. ________________ crosses are
performed between two parents that differ in only one trait, and ______________ crosses are
performed between parents that differ in two traits.
Mendel started each cross with true-breeding parents. We now refer to these parents as
having a genotype that is _________________ because both alleles are the ________. In each
cross Mendel noted that one trait would disappear in the F1 generation, only to reappear
unchanged in the F2 generation. The trait that always appeared in the F1 hybrids he referred to as
the __________________ trait while the trait that disappeared in the F1 generation he called the
_________________ trait. The F1 hybrids have a genotype called _____________________
because they have two ____________________ alleles.
Using the traits listed below fill in the chart provided and answer the questions.
R = red flowers
Y = yellow peas
I = inflated
B = black fur
F = freckles
W = widow’s peak
Trait
Flower color
Fur color
Freckles
r = white flowers
y = green peas
I = constricted
b = brown fur
f = no freckles
w = no widow’s peak
Homozygous
Homozygous
dominant
Heterozygous
recessive
genotype
genotype
genotype
Dominant
phenotype
Recessive
Phenotype
1. If you cross two pea plants that are both heterozygous for yellow peas, what phenotypic ration would
result in the offspring?
2. What are the genotypes if one parent is homozygous dominant for black fur and the other has brown
fur?
3. If you cross one parent that is heterozygous for inflated pods and the other has constricted pods,
what genotypic ratio would result in the offspring?
4. If a man heterozygous for freckles marries a woman who has no freckles, what are the chances their
children would have freckles?
5. If a man heterozygous for a widow’s peak marries a woman who is also heterozygous for a widow’s
peak, what are the possible offspring phenotypes and the likelihood of each?
Fill in the blank using the options provided below, use 46 twice:
1
22
44
46
autosomes
extra
gender
meiosis
missing
monosomy
nondisjunction
pairs
trisomy
Down’s Syndrome
Turner Syndrome
XY
Y
X
XX
In humans chromosomes exist in ______ in each body cell. Each human has ____ pairs
of autosomes for a total of ____ and ___ pair of sex chromosomes, resulting in ____ total
chromosomes. The sex chromosomes determine the __________, or sex of the individual and
are designated as the ___ or ___ chromosome. Human males have the sex genotype ______ and
human females have the sex genotype _____. ___________________ are the other 22 pairs of
chromosomes that are not sex chromosomes.
Normal __________, gamete formation, and fertilization ensure that each human ends up
with exactly ____ chromosomes. Sometimes during meiosis chromosomes fail to separate
properly through a process called __________________________ and gametes result in having
an ___________ or a _____________chromosome. If these gametes containing too many or too
few chromosomes are fertilized the resulting zygote will have an extra chromosome, called
_______________, such as ___________________________ or Trisomy 21. If they are missing
a chromosome it is called _____________________, such as
_____________________________ or Monosomy X.
Fill out the chart below:
Human Trait
Inheritance Pattern
Cystic fibrosis
Simple dominance
XH = normal
Xh = hemophilia
Hemophilia
Color Blindness
Blood Type
Skin Color
Alleles
Sex-linked
A
B
O
Do not have to know
alleles for this trait.
6. Using the alleles (R) = red flowers and (r) or (R’) = white flowers, explain or demonstrate how
the results would be different if the trait were controlled by incomplete dominance vs. codominance.
7. If a colorblind father marries a woman who is a carrier, what are the chances of them having a
colorblind child?
8. This pedigree shows a trait that is (autosomal/sex-linked) (dominant/recessive).
9. What is the relationship between individuals I-2 and III-3?
a. mother and daughter
b. father and son
c. grandmother and granddaughter
d. grandfather and grandson
10. If the trait in the above pedigree is hemophilia, assign genotypes to the following individuals:
I-1: _________
II-2: __________
III-2: __________
11. This pedigree shows a trait that is (autosomal/sex-linked) (dominant/recessive).
12. What is the relationship between individuals I-1 and II-2?
a. mother and daughter
b. father and son
c. grandmother and granddaughter
d. grandfather and grandson
13. If the trait in the above pedigree is cystic fibrosis, assign genotypes to the following
individuals:
I-1: _________
I-2: __________
II-2: __________
II-3: __________