Bio 340 Test 2 Questions with Verified Correct
Answers
If black and white true-breeding mice are mated and the result is all gray offspring, what
inheritance pattern would this be indicative of?
incomplete dominance
ABO blood groups are examples of:
Multiple alleles and codominance
Could an individual with blood type O (genotype ii) be a legitimate child of parents in
which one parent had blood type A and the other parent had blood type B?
Yes, if each parent carries one i allele.
A white splashed (Bl/Bl) Andalausian chicken and a black (bl/bl) Andalusian chicken are
crossed. The heterozygotes produced show an intermediate phenotype (blue). What
inheritance pattern would this be indicative of?
incomplete dominance
A person with only one sickle cell anemia allele and one unaffected allele will have some
normal blood cells and some abnormal. What inheritance pattern would this be indicated
of?
Codominance
In a mating between two individuals that are heterozygous for a recessive lethal allele that
is expressed in utero, what genotypic ratio (homozygous
, dominant:heterozygous:homozygous recessive) would you expect to observe in the
offspring?
1:2:0
The wild-type coat color, agouti (AA) is dominant to solid-colored fur (aa). However, a
separate gene C, when present as the recessive homozygote (cc), negates any expression of
pigment from the A gene and results in an albino mouse. Therefore, the genotypes AAcc,
Aacc, and aacc all produce the same albino phenotype. A cross between heterozygotes for
both genes (AaCc x AaCc) would generate offspring with a phenotypic ratio of 9 agouti:3
black:4 albino. Which type of gene interaction is this?
recessive epistasis
Wild type blue-eyed mary has blue flowers. Two genes
control the pathway that makes the blue pigment: The
product of gene Wturns a white precursor into magenta
pigment. The product of gene M turns the magenta
pigment into blue pigment. Each gene has a recessive
loss-of-function allele: w and m, respectively. A double
heterozygote (Ww Mm) is self-pollinated. What
proportion of offspring will be magenta?
3/16
Define codominance
both alleles being present
Answers
If black and white true-breeding mice are mated and the result is all gray offspring, what
inheritance pattern would this be indicative of?
incomplete dominance
ABO blood groups are examples of:
Multiple alleles and codominance
Could an individual with blood type O (genotype ii) be a legitimate child of parents in
which one parent had blood type A and the other parent had blood type B?
Yes, if each parent carries one i allele.
A white splashed (Bl/Bl) Andalausian chicken and a black (bl/bl) Andalusian chicken are
crossed. The heterozygotes produced show an intermediate phenotype (blue). What
inheritance pattern would this be indicative of?
incomplete dominance
A person with only one sickle cell anemia allele and one unaffected allele will have some
normal blood cells and some abnormal. What inheritance pattern would this be indicated
of?
Codominance
In a mating between two individuals that are heterozygous for a recessive lethal allele that
is expressed in utero, what genotypic ratio (homozygous
, dominant:heterozygous:homozygous recessive) would you expect to observe in the
offspring?
1:2:0
The wild-type coat color, agouti (AA) is dominant to solid-colored fur (aa). However, a
separate gene C, when present as the recessive homozygote (cc), negates any expression of
pigment from the A gene and results in an albino mouse. Therefore, the genotypes AAcc,
Aacc, and aacc all produce the same albino phenotype. A cross between heterozygotes for
both genes (AaCc x AaCc) would generate offspring with a phenotypic ratio of 9 agouti:3
black:4 albino. Which type of gene interaction is this?
recessive epistasis
Wild type blue-eyed mary has blue flowers. Two genes
control the pathway that makes the blue pigment: The
product of gene Wturns a white precursor into magenta
pigment. The product of gene M turns the magenta
pigment into blue pigment. Each gene has a recessive
loss-of-function allele: w and m, respectively. A double
heterozygote (Ww Mm) is self-pollinated. What
proportion of offspring will be magenta?
3/16
Define codominance
both alleles being present
