BIOS 1700 Final Exam Review Questions with Correct Answers Latest Update 2025/2026
Which phases are shown in figures below? - Answers
Which DNA sequences are more alike: a pair of sister chromatids or a pair of homologous
chromosomes? - Answers Sister chromatids
Which two processes in meiotic cell division lead to increased genetic variation in daughter cells?
- Answers Crossing over and independent assortment
What would be the ratio of yellow and green seeds in the F2 generation if the F1 plant produced
A and a gametes in the 2/3 to 1/3 ratio respectively? - Answers 8:1
Does this prediction support Mendel's first law, equal segregation? - Answers No, it does not
support Mendel's first law since it does not match the observed ratio of 3 to 1.
How many units of enzyme does a heterozygote r/r+ produce if the wild type allele produces 10
units? - Answers 10 units
Is 10 units of enzyme produced by the heterozygote more or less than 16 units? - Answers Less
In chickens, what do the upper case letters C and I represent? - Answers Wild type alleles for
pigment-producing enzyme and inhibitor.
What is the phenotype of a true-breeding short-haired male cat (SS) mated to a long-haired
female (ss)? - Answers All of the kittens will have short hair.
What is the genotype of the second parent cat if two short-haired and three long-haired kittens
are produced? - Answers The second parent is heterozygous short-haired (Ss).
What do you know about the genotype of the parents of a child with Tay-Sachs? - Answers The
parents must both be heterozygous.
What percentage of their children survives if both parents are heterozygous for Tay-Sachs? -
Answers 3/4
What is the probability that all of the surviving children of heterozygous parents are carriers of
Tay-Sachs? - Answers ~30% (8/27).
If a daughter with Tay-Sachs has children with a man with no known family history of the
disease, what is the probability their children will have Tay-Sachs? - Answers Extremely low.
Is it more likely for males or females to get Tay-Sachs disease? - Answers Both males and
females have the same probability since it is autosomal.
What can be inferred about a Drosophila female that produces offspring with both white and red
eyes? - Answers The trait is likely X-linked.
, What is the genotype of the Drosophila female if half of her male offspring have white eyes? -
Answers X+Xw.
What is the chance of being a carrier for a recessive deafness mutation if both parents have
normal hearing and the sister is deaf? - Answers
What is the genotype of a color-blind boy in a family with red-green color blindness? - Answers
XbY
What is the genotype of a color-blind girl in a family with red-green color blindness? - Answers
XbXb
What must be true about the father if the son is color-blind? - Answers The father must be color-
blind.
What is the expected number of black, winged flies (Bbnn) in the F2 generation if traits are
linked? - Answers 800 black, winged flies.
What is the expected number of brown, winged flies (BbNn) in the F2 generation if traits are
linked? - Answers 0 brown, winged flies.
What is the genetic distance between the color and wing genes based on observed
recombination events? - Answers 10 map units.
What is the concordance rate among identical twins if 70 pairs share a trait and 40 do not? -
Answers 63.6%.
What factor is likely to have a larger impact on a trait if concordance among identical twins is
high? - Answers Genetic factors.
What does it suggest if strain B mice develop diabetes while strain A mice do not when fed a
high sugar and fat diet? - Answers The genetic composition of strain B is not suited for such
diets.
What is a possible reason why Agouti mutant pups look normal despite having the mutation? -
Answers Methylation induced by the mother's diet inactivated the Agouti mutation.
What is the genetic composition of a rare male calico cat? - Answers XXY trisomy.
What is the significance of X-inactivation in calico cats? - Answers It is a random process
affecting coat color.
What does it mean if a virus is described as 'naked'? - Answers It has no membrane envelope.
Which virus is more likely to be spread via the oral-fecal route? - Answers Poliovirus.
What is the role of reverse transcriptase in viruses? - Answers It copies RNA into DNA.
Which phases are shown in figures below? - Answers
Which DNA sequences are more alike: a pair of sister chromatids or a pair of homologous
chromosomes? - Answers Sister chromatids
Which two processes in meiotic cell division lead to increased genetic variation in daughter cells?
- Answers Crossing over and independent assortment
What would be the ratio of yellow and green seeds in the F2 generation if the F1 plant produced
A and a gametes in the 2/3 to 1/3 ratio respectively? - Answers 8:1
Does this prediction support Mendel's first law, equal segregation? - Answers No, it does not
support Mendel's first law since it does not match the observed ratio of 3 to 1.
How many units of enzyme does a heterozygote r/r+ produce if the wild type allele produces 10
units? - Answers 10 units
Is 10 units of enzyme produced by the heterozygote more or less than 16 units? - Answers Less
In chickens, what do the upper case letters C and I represent? - Answers Wild type alleles for
pigment-producing enzyme and inhibitor.
What is the phenotype of a true-breeding short-haired male cat (SS) mated to a long-haired
female (ss)? - Answers All of the kittens will have short hair.
What is the genotype of the second parent cat if two short-haired and three long-haired kittens
are produced? - Answers The second parent is heterozygous short-haired (Ss).
What do you know about the genotype of the parents of a child with Tay-Sachs? - Answers The
parents must both be heterozygous.
What percentage of their children survives if both parents are heterozygous for Tay-Sachs? -
Answers 3/4
What is the probability that all of the surviving children of heterozygous parents are carriers of
Tay-Sachs? - Answers ~30% (8/27).
If a daughter with Tay-Sachs has children with a man with no known family history of the
disease, what is the probability their children will have Tay-Sachs? - Answers Extremely low.
Is it more likely for males or females to get Tay-Sachs disease? - Answers Both males and
females have the same probability since it is autosomal.
What can be inferred about a Drosophila female that produces offspring with both white and red
eyes? - Answers The trait is likely X-linked.
, What is the genotype of the Drosophila female if half of her male offspring have white eyes? -
Answers X+Xw.
What is the chance of being a carrier for a recessive deafness mutation if both parents have
normal hearing and the sister is deaf? - Answers
What is the genotype of a color-blind boy in a family with red-green color blindness? - Answers
XbY
What is the genotype of a color-blind girl in a family with red-green color blindness? - Answers
XbXb
What must be true about the father if the son is color-blind? - Answers The father must be color-
blind.
What is the expected number of black, winged flies (Bbnn) in the F2 generation if traits are
linked? - Answers 800 black, winged flies.
What is the expected number of brown, winged flies (BbNn) in the F2 generation if traits are
linked? - Answers 0 brown, winged flies.
What is the genetic distance between the color and wing genes based on observed
recombination events? - Answers 10 map units.
What is the concordance rate among identical twins if 70 pairs share a trait and 40 do not? -
Answers 63.6%.
What factor is likely to have a larger impact on a trait if concordance among identical twins is
high? - Answers Genetic factors.
What does it suggest if strain B mice develop diabetes while strain A mice do not when fed a
high sugar and fat diet? - Answers The genetic composition of strain B is not suited for such
diets.
What is a possible reason why Agouti mutant pups look normal despite having the mutation? -
Answers Methylation induced by the mother's diet inactivated the Agouti mutation.
What is the genetic composition of a rare male calico cat? - Answers XXY trisomy.
What is the significance of X-inactivation in calico cats? - Answers It is a random process
affecting coat color.
What does it mean if a virus is described as 'naked'? - Answers It has no membrane envelope.
Which virus is more likely to be spread via the oral-fecal route? - Answers Poliovirus.
What is the role of reverse transcriptase in viruses? - Answers It copies RNA into DNA.
