BIO 1404 Exam (Latest 2024/25) Questions
& 100% Correct Answers Graded A+
A scientist pollinates a true-breeding pea plant with violet, terminal flowers with pollen from a true-
breeding pea plant with white, axial flowers. Which of the following observations would most
accurately describe the F2 generation? - ✔✔75% violet flowers; 75% axial flowers
The observable traits expressed by an organism are described as its ________. - ✔✔phenotype
A recessive trait will be observed in individuals that are ________ for that trait. - ✔✔homozygous
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
The ABO blood groups in humans are expressed as the IA, IB, and i alleles. The IA allele encodes the A
blood group antigen, IB encodes B, and i encodes O. Both A and B are dominant to O. If a heterozygous
blood type A parent (IAi) and a heterozygous blood type B parent (IBi) mate, one quarter of their
offspring will have AB blood type (IAIB) in which both antigens are expressed equally. Therefore, ABO
blood groups are an example of: - ✔✔multiple alleles and 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
If the allele encoding polydactyly (six fingers) is dominant why do most people have five fingers? -
✔✔The polydactyl allele is very rare in the human population.
A farmer raises black and white chickens. To his surprise, when the first generation of eggs hatch all
the chickens are black with white speckles throughout their feathers. What should the farmer expect
when the eggs laid after interbreeding the speckled chickens hatch? - ✔✔50% of the offspring will
be speckled, 25% will be black, and 25% will be white.
Assuming no gene linkage, in a dihybrid cross of AABB x aabb with AaBb F1 heterozygotes, what is the
ratio of the F1 gametes (AB, aB, Ab, ab) that will give rise to the F2 offspring? - ✔✔1:1:1:1
, The forked line and probability methods make use of what probability rule? - ✔✔product rule
How many different offspring genotypes are expected in a trihybrid cross between parents
heterozygous for all three traits when the traits behave in a dominant and recessive pattern? How many
phenotypes? - ✔✔27 genotypes; 8 phenotypes
Labrador retriever's fur color is controlled by two alleles, E and B. Any dog with the ee__ genotype
develops into a yellow lab, while B_E_ dogs become black labs and bbE_ dogs become chocolate labs.
This is an example of _____. - ✔✔epistasis
Which of the following situations does not follow the Law of Independent Assortment? - ✔✔Men
are more likely to experience hemophilia than women.
X-linked recessive traits in humans (or in Drosophila) are observed ________. - ✔✔in more males
than females
The first suggestion that chromosomes may physically exchange segments came from the microscopic
identification of ________. - ✔✔chiasmata
Which recombination frequency corresponds to independent assortment and the absence of linkage?
- ✔✔0.50
Which recombination frequency corresponds to perfect linkage and violates the law of
independent assortment? - ✔✔0
Which of the following codes describes position 12 on the long arm of chromosome 13? - ✔✔13q12
In agriculture, polyploid crops (like coffee, strawberries, or bananas) tend to produce ________. -
✔✔larger yields
& 100% Correct Answers Graded A+
A scientist pollinates a true-breeding pea plant with violet, terminal flowers with pollen from a true-
breeding pea plant with white, axial flowers. Which of the following observations would most
accurately describe the F2 generation? - ✔✔75% violet flowers; 75% axial flowers
The observable traits expressed by an organism are described as its ________. - ✔✔phenotype
A recessive trait will be observed in individuals that are ________ for that trait. - ✔✔homozygous
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
The ABO blood groups in humans are expressed as the IA, IB, and i alleles. The IA allele encodes the A
blood group antigen, IB encodes B, and i encodes O. Both A and B are dominant to O. If a heterozygous
blood type A parent (IAi) and a heterozygous blood type B parent (IBi) mate, one quarter of their
offspring will have AB blood type (IAIB) in which both antigens are expressed equally. Therefore, ABO
blood groups are an example of: - ✔✔multiple alleles and 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
If the allele encoding polydactyly (six fingers) is dominant why do most people have five fingers? -
✔✔The polydactyl allele is very rare in the human population.
A farmer raises black and white chickens. To his surprise, when the first generation of eggs hatch all
the chickens are black with white speckles throughout their feathers. What should the farmer expect
when the eggs laid after interbreeding the speckled chickens hatch? - ✔✔50% of the offspring will
be speckled, 25% will be black, and 25% will be white.
Assuming no gene linkage, in a dihybrid cross of AABB x aabb with AaBb F1 heterozygotes, what is the
ratio of the F1 gametes (AB, aB, Ab, ab) that will give rise to the F2 offspring? - ✔✔1:1:1:1
, The forked line and probability methods make use of what probability rule? - ✔✔product rule
How many different offspring genotypes are expected in a trihybrid cross between parents
heterozygous for all three traits when the traits behave in a dominant and recessive pattern? How many
phenotypes? - ✔✔27 genotypes; 8 phenotypes
Labrador retriever's fur color is controlled by two alleles, E and B. Any dog with the ee__ genotype
develops into a yellow lab, while B_E_ dogs become black labs and bbE_ dogs become chocolate labs.
This is an example of _____. - ✔✔epistasis
Which of the following situations does not follow the Law of Independent Assortment? - ✔✔Men
are more likely to experience hemophilia than women.
X-linked recessive traits in humans (or in Drosophila) are observed ________. - ✔✔in more males
than females
The first suggestion that chromosomes may physically exchange segments came from the microscopic
identification of ________. - ✔✔chiasmata
Which recombination frequency corresponds to independent assortment and the absence of linkage?
- ✔✔0.50
Which recombination frequency corresponds to perfect linkage and violates the law of
independent assortment? - ✔✔0
Which of the following codes describes position 12 on the long arm of chromosome 13? - ✔✔13q12
In agriculture, polyploid crops (like coffee, strawberries, or bananas) tend to produce ________. -
✔✔larger yields
