BIO 211 HOMEWORK EXAM 4 QUESTIONS AND ANSWERS
An individual possesses two alleles at a locus and these two alleles separate when gametes are formed,
one allele going into each gamete. This genetic concept is known as what? - CORRECT
ANSWER✅✅principle of segregation
What will the genotypic ratio in the offspring of two Aa parents that are crossed with each other? -
CORRECT ANSWER✅✅1 : 2 : 1
Suppose that two parents are both heterozygous for sickle cell anemia, which is an autosomal recessive
disease. They have seven children.
Use the binomial theorem to determine the probability that three of the children have sickle cell anemia
and four of the children are healthy. Round your answer to the nearest hundredth. - CORRECT
ANSWER✅✅0.2
In fruit flies, gray bodies (G) are dominant over black bodies (g), and red eyes (R) are dominant over
orange eyes (r). Each individual possesses two alleles for each trait.
If a fly that is homozygous dominant for both traits is crossed with a fly that is homozygous recessive for
both traits, what is the predicted genotype of the offspring? - CORRECT ANSWER✅✅GgRr
In a hypothetical mouse species, brown fur (B) is completely dominant to white fur (b), and long fur (L) is
completely dominant to short fur (l). If two mice heterozygous for both traits mate and produce a litter
of pups, what is the probability that an individual pup will have brown, short fur? - CORRECT
ANSWER✅✅3/16
Suppose Stephen breeds flowers and wants to optimize production of offspring with both short stems
and white flowers, which are coded for by two genes with the recessive alleles t and p, respectively. In
flowers, T codes for tall stems and P codes for purple flowers. Stephen crosses two heterozygotes that
produce 544 offspring.
How many of these 544 offspring are predicted to have both short stems and white flowers? - CORRECT
ANSWER✅✅34
, When Mendel crossed a plant homozygous for round seeds to another plant homozygous for wrinkled
seeds, he found that all the progeny had round seeds. How is this explained? - CORRECT
ANSWER✅✅the allele for round seeds is dominant to the allele for wrinkled seeds
If an Aa individual is crossed to an aa individual, what will be the phenotypic ratio in the offspring? -
CORRECT ANSWER✅✅1 : 1
A cross between an AABB and an aabb will produce what type of offspring? - CORRECT ANSWER✅✅all
will be AaBb
What information can the chi-square goodness-of-fit test provide? - CORRECT ANSWER✅✅how well
the observed results of a genetic cross fit the expected values
When you cross two heterozygous black cats (Bb), the expected Mendelian phenotypic ratio of black
(B_) to gray (bb) offspring is? - CORRECT ANSWER✅✅black : gray = 3 : 1
List the steps in performing chi-square tests correctly.
A. Calculating the X^2 value using expected and observed values
B. Comparing the P value to the cutoff P value of 0.05
C. Calculating degrees of freedom (df)
D. Calculating the expected progeny counts
E. Determining the P value range from the chi-square table
F. Determining the X^2 value range from the chi-square table
An individual possesses two alleles at a locus and these two alleles separate when gametes are formed,
one allele going into each gamete. This genetic concept is known as what? - CORRECT
ANSWER✅✅principle of segregation
What will the genotypic ratio in the offspring of two Aa parents that are crossed with each other? -
CORRECT ANSWER✅✅1 : 2 : 1
Suppose that two parents are both heterozygous for sickle cell anemia, which is an autosomal recessive
disease. They have seven children.
Use the binomial theorem to determine the probability that three of the children have sickle cell anemia
and four of the children are healthy. Round your answer to the nearest hundredth. - CORRECT
ANSWER✅✅0.2
In fruit flies, gray bodies (G) are dominant over black bodies (g), and red eyes (R) are dominant over
orange eyes (r). Each individual possesses two alleles for each trait.
If a fly that is homozygous dominant for both traits is crossed with a fly that is homozygous recessive for
both traits, what is the predicted genotype of the offspring? - CORRECT ANSWER✅✅GgRr
In a hypothetical mouse species, brown fur (B) is completely dominant to white fur (b), and long fur (L) is
completely dominant to short fur (l). If two mice heterozygous for both traits mate and produce a litter
of pups, what is the probability that an individual pup will have brown, short fur? - CORRECT
ANSWER✅✅3/16
Suppose Stephen breeds flowers and wants to optimize production of offspring with both short stems
and white flowers, which are coded for by two genes with the recessive alleles t and p, respectively. In
flowers, T codes for tall stems and P codes for purple flowers. Stephen crosses two heterozygotes that
produce 544 offspring.
How many of these 544 offspring are predicted to have both short stems and white flowers? - CORRECT
ANSWER✅✅34
, When Mendel crossed a plant homozygous for round seeds to another plant homozygous for wrinkled
seeds, he found that all the progeny had round seeds. How is this explained? - CORRECT
ANSWER✅✅the allele for round seeds is dominant to the allele for wrinkled seeds
If an Aa individual is crossed to an aa individual, what will be the phenotypic ratio in the offspring? -
CORRECT ANSWER✅✅1 : 1
A cross between an AABB and an aabb will produce what type of offspring? - CORRECT ANSWER✅✅all
will be AaBb
What information can the chi-square goodness-of-fit test provide? - CORRECT ANSWER✅✅how well
the observed results of a genetic cross fit the expected values
When you cross two heterozygous black cats (Bb), the expected Mendelian phenotypic ratio of black
(B_) to gray (bb) offspring is? - CORRECT ANSWER✅✅black : gray = 3 : 1
List the steps in performing chi-square tests correctly.
A. Calculating the X^2 value using expected and observed values
B. Comparing the P value to the cutoff P value of 0.05
C. Calculating degrees of freedom (df)
D. Calculating the expected progeny counts
E. Determining the P value range from the chi-square table
F. Determining the X^2 value range from the chi-square table
