A child with type AB blood could not be the offspring of a man with type ___ blood.
A
B
AB
O
Answer: B
A gene that masks the expression of a second gene is
haplosufficient.
incompletely dominant.
epistatic.
homeostatic.
Answer: C
A man with the A blood type marries a woman with blood type B. Which blood type or types could their children have?
A
B
O
A, B, AB, or O
Answer: D
People with which of the following blood types can receive a transfusion from a type O donor?
type A
type B
type AB
A, B, or AB
Answer: D
For an autosomal gene with three alleles, a diploid cell may have up to how many different alleles of that gene?
0
1
2
3
Answer: C
A monohybrid cross for a trait with incomplete dominance yielded 200 offspring. ______ of these are expected to exhibit the intermediate phenotype.
50
100
150
All 200
Answer: B
In a cross involving a genetic locus with an allele for red color and one for white, some of the progeny appear both red and white. This is an example of
complete dominance.
incomplete dominance.
codominance.
irregular dominance.
Answer: C
In a particular population carrying a dominant mutant allele, only 70% of the people carrying the allele show the phenotype, and only a small percentage of those showing the phenotype display the most severe symptoms. The gene responsible for this disorder exhibits
incomplete penetrance and epistasis.
epistasis and variable expressivity.
variable expressivity and incomplete penetrance.
incomplete penetrance and incomplete dominance.
Answer: C
In certain types of sheep, horns are a trait limited to males, although both male and female sheep carry the genes for horns. This is an example of a ___ trait.
sex-linked
sex-limited
sex-influenced
sex-determined
Answer: B
In gremlins, coat color is determined by a gene with multiple alleles. The three alleles involved are: B (brown color); b (white color); and b a (brown and white stripes). For this locus, B is dominant to both b and b a , and b a is dominant to b . In a cross between a B / b a male gremlin and a B / b female gremlin, what percentage of the offspring will have brown and white stripes?
0
25
50
100
Answer: B
In the M-N blood group system, a heterozygote for the L M and L N alleles will express which antigen on the blood cell surfaces?
M only
N only
both M and N
neither M or N
Answer: C
Members of a particular family carry a dominant gene that causes their index and ring fingers to be webbed. Although all of the children carry the dominant allele, only seven of the ten children in this family have the webbed phenotype. This indicates that the gene involved in this phenotype is
completely dominant.
incompletely dominant.
incompletely penetrant.
epistatic.
Answer: C
Pattern baldness in men is an example of a ___ trait.
sex-linked
sex-limited
sex-influenced
sex-determined
Answer: C
Huntington disease is an example of
a dominant lethal allele.
a recessive lethal disease.
dominant epistasis.
recessive epistasis
Answer: A
The expression of the pattern baldness phenotype in men is directly related to their
age.
nutritional pattern.
exposure to dangerous chemicals.
level of stress.
Answer: A
The gene for red hair color in Smurfs masks the expression of a
second gene for orange hair. The gene for orange hair is ___ to the
gene for red hair.
epistatic
incompletely dominant
hypostatic
haplosufficient
Answer: C
The genotype of a person with type O blood is
ii .
I A I A .
I A i .
I B i .
Answer: A
A dihybrid cross for two kernel color genes in corn yields the phenotypic ratio 9:3:4. What is the most likely explanation for this ratio?
incomplete dominance
lethal allele
epistasis
incomplete penetrance
Answer: C
If there are four types of homozygotes for a given gene in a diploid, how many alleles are there for this gene?
1
2
3
4
Answer: D
An allele mutation that leads to the overproduction of a gene product is expected to express in _____ fashion.
recessive
codominant
incompletely dominant
dominant
Answer: D
A cross between two heterozygotes gives a 1:2 genotypic ratio in the offspring. This is probably due to
epistasis.
a recessive lethal allele.
a dominant lethal allele.
incomplete dominance.
Answer: B
A cross between a pink flower and a white flower produces 1/2 pink and 1/2 white flowers. A cross between a red flower and a pink flower produces 1/2 red flowers and 1/2 pink flowers. What is this an example of?
complete dominance
incomplete dominance
codominance
environmental effects
Answer: B
Five plants of the same genotype are different shades of green. This may be an example of
constant expressivity.
complete penetrance.
variable expressivity
incomplete penetrance
Answer: C
When the offspring of a mating all have the same phenotype for a trait as the female parent, this is an example of
maternal effect.
paternal effect
complete dominance
codominance
Answer: A
A cross between two true-breeding mutant flies for a given trait leads to all wild-type flies for that trait. This is an example of
maternal effect.
incomplete dominance.
incomplete penetrance
complementation
Answer: D