Think you’ve got your head wrapped around Genetics? Put your knowledge to
the test. Good luck — the Stickman is counting on you!
Q. In what inheritance patterns does the genotypic ratio match the phenotypic ratio?
Pleiotropy and codominance
Additive genetic variance
Codominance and incomplete dominance
Incomplete dominance and epistasis
All Mendelian traits
Q. Alleles are different _______ of a gene.
loci
forms
fragments
chromosomes
halves
Q. The presence of freckles is a dominant Mendelian trait in humans. If your cousin has freckles, but her husband doesn’t, what are the chances that their baby will have freckles?
Not enough information is provided.
Either 50% or 100%
33%
0%
Either 25% or 75%
Q. Hemophilia is an X-linked recessive bleeding disorder. If a normal woman whose father was a hemophiliac marries a normal man, what are the chances of their children having the disease?
None
½ for a boy and ½ for a girl
½ for a boy and none for a girl
¾ for a boy and ¼ for a girl
4/4
Q. A cross between a tomato cultivar producing fruit weighing, on average, 4 oz and another producing fruit weighing, on average, 6 oz generates offspring plants bearing fruits that weigh, on average, 8 oz. A possible explanation for this observation could be
pleiotropy
codominance
epistatic genetic variance
additive genetic variance
incomplete penetrance
Q. A wild type phenotype
is dominant
shows a wild pattern of inheritance
is the most common phenotype in a population
is not affected by the environment
is Mendelian
Q. If John’s grandmother on his mother’s side had a mitochondrial disorder, how likely is he to inherit it?
0%
25%
50%
75%
100%
Q. Mutations in the Rb gene can cause retinoblastoma, a cancer that affects the retina. However, not every individual carrying the disease-causing mutation develops the disease. This phenomenon is known as
incomplete penetrance
partial dominance
complete epistasis
variable expressivity
genetic variance
Q. In an attempt to reduce the number of bullocks born, which are no use to him for producing milk, a farmer has paid to have his diary herd artificially inseminated with sperm that has had half the sperm carrying a Y chromosome removed. What female-to-male ratio would you expect to see in the calves produced from this procedure?
1:1
1.5:1
2:1
3:1
All female
Q. A cat breeder has two Manx cats. What phenotypic ratio of offspring can she expect after mating them together?
3 Manx : 1 tailed
2 Manx : 1 tailed
1 Manx : 1 tailed
All Manx
All tailed