GCD EXAM 1 QUESTIONS AND
CORRECT DETAILED ANSWERS
WITH RATIONALES ALREADY
GRADED A+
Morgan observed a higher number of recombinant offspring involving eye color and
wing length (401 + 318) compared to body color and eye color (17 + 12). These results
occurred because - Answer-the genes affecting eye color and wing length are farther
apart on the X chromosome compared to the genes affecting body color and eye color.
In genetics, the term "linkage" means that - Answer-both a and b are correct.
A person with Down syndrome is - Answer-Aneuploid
The technique of genomic hybridization is used to detect - Answer-chromosomal
deletions and duplications.
Which of the following individuals (say a plant) would be the most likely to be fertile? -
Answer-Allotetraploid
A person with trisomy-18 exhibits a collection of abnormalities that affect many organs
including the brain. These abnormalities occur because - Answer-there is an imbalance
in gene expression.
A crossover between nonhomologous chromosomes during meiosis results in - Answer-
a reciprocal translocation.
Which of the following statements is correct?
Select one:
a. If a deletion and duplication are the same size, the likelihood of causing harm is
about the same.
b. If a deletion and duplication are the same size, the deletion is more likely to be
harmful.
c. If a deletion and duplication are the same size, the duplication is more likely to be
harmful.
d. A deletion is always harmful whereas a duplication is always beneficial. - Answer-If a
deletion and duplication are the same size, the deletion is more likely to be harmful.
The members of a gene family usually have differences in their DNA sequences
because - Answer-they accumulate different random mutations.
, A person inherits an extra copy of chromosome 21 from their mother. This is most likely
due to - Answer-nondisjunction during meiosis I.
A misaligned crossover between homologues during meiosis results in - Answer--a
chromosome with a deletion.
-a chromosome with a duplication.
When making a karyotype, which of the following features is used to characterize
eukaryotic chromosomes?
a. Banding patterns
b. Centromere location
c. Size
d. All of the above - Answer-Banding patterns
Centromere location
Size
χ2 = Σ (O - E)2/E - Answer-O = observed data in each category
E = expected data in each category based on the experimenter's hypothesisΣ
= Sum of the calculations for each category
The length of the index finger is sex-influenced. The short allele is dominant in males,
whereas the long allele is dominant in females. If a heterozygous male and a female
with short index fingers have offspring together, what are the possible phenotypes of the
offspring? - Answer-males with short index fingers and females with short or long index
fingers
Which of the following statements is false?
Select one:
a. A true-breeding individual is homozygous.
b. An allele is a gene.
c. For most species, a chromosome carries a single gene.
d. A heterozygote has different alleles for a given gene. - Answer-c. For most species, a
chromosome carries a single gene. Correct
A heterozygous plant, GgHhIiJjKk is allowed to self fertilize. What is the probability that
an offspring will be GGHhIiJjkk?
Select one:
a. 1/128 = 0.0078
b. 243/1024 = 0.24
c. 1/1024 = 0.00098
d. 1/4 = 0.75 - Answer-1/128 = 0.0078
Hemophilia, type A, is an X-linked recessive trait. A mother without hemophilia and a
father with hemophilia have a daughter with hemophilia. If their next offspring is a son,
which is the likelihood that this son will have hemophilia? - Answer-50%
A female who is IA i has offspring with a father who IB IB. Which blood type(s) would
not be possible for their offspring? - Answer-Type A and Type O
CORRECT DETAILED ANSWERS
WITH RATIONALES ALREADY
GRADED A+
Morgan observed a higher number of recombinant offspring involving eye color and
wing length (401 + 318) compared to body color and eye color (17 + 12). These results
occurred because - Answer-the genes affecting eye color and wing length are farther
apart on the X chromosome compared to the genes affecting body color and eye color.
In genetics, the term "linkage" means that - Answer-both a and b are correct.
A person with Down syndrome is - Answer-Aneuploid
The technique of genomic hybridization is used to detect - Answer-chromosomal
deletions and duplications.
Which of the following individuals (say a plant) would be the most likely to be fertile? -
Answer-Allotetraploid
A person with trisomy-18 exhibits a collection of abnormalities that affect many organs
including the brain. These abnormalities occur because - Answer-there is an imbalance
in gene expression.
A crossover between nonhomologous chromosomes during meiosis results in - Answer-
a reciprocal translocation.
Which of the following statements is correct?
Select one:
a. If a deletion and duplication are the same size, the likelihood of causing harm is
about the same.
b. If a deletion and duplication are the same size, the deletion is more likely to be
harmful.
c. If a deletion and duplication are the same size, the duplication is more likely to be
harmful.
d. A deletion is always harmful whereas a duplication is always beneficial. - Answer-If a
deletion and duplication are the same size, the deletion is more likely to be harmful.
The members of a gene family usually have differences in their DNA sequences
because - Answer-they accumulate different random mutations.
, A person inherits an extra copy of chromosome 21 from their mother. This is most likely
due to - Answer-nondisjunction during meiosis I.
A misaligned crossover between homologues during meiosis results in - Answer--a
chromosome with a deletion.
-a chromosome with a duplication.
When making a karyotype, which of the following features is used to characterize
eukaryotic chromosomes?
a. Banding patterns
b. Centromere location
c. Size
d. All of the above - Answer-Banding patterns
Centromere location
Size
χ2 = Σ (O - E)2/E - Answer-O = observed data in each category
E = expected data in each category based on the experimenter's hypothesisΣ
= Sum of the calculations for each category
The length of the index finger is sex-influenced. The short allele is dominant in males,
whereas the long allele is dominant in females. If a heterozygous male and a female
with short index fingers have offspring together, what are the possible phenotypes of the
offspring? - Answer-males with short index fingers and females with short or long index
fingers
Which of the following statements is false?
Select one:
a. A true-breeding individual is homozygous.
b. An allele is a gene.
c. For most species, a chromosome carries a single gene.
d. A heterozygote has different alleles for a given gene. - Answer-c. For most species, a
chromosome carries a single gene. Correct
A heterozygous plant, GgHhIiJjKk is allowed to self fertilize. What is the probability that
an offspring will be GGHhIiJjkk?
Select one:
a. 1/128 = 0.0078
b. 243/1024 = 0.24
c. 1/1024 = 0.00098
d. 1/4 = 0.75 - Answer-1/128 = 0.0078
Hemophilia, type A, is an X-linked recessive trait. A mother without hemophilia and a
father with hemophilia have a daughter with hemophilia. If their next offspring is a son,
which is the likelihood that this son will have hemophilia? - Answer-50%
A female who is IA i has offspring with a father who IB IB. Which blood type(s) would
not be possible for their offspring? - Answer-Type A and Type O
