Question 1

They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?

Accepted Answer

A)  0
B)  0.25
C)  0.50
D)  0.75
E)  1.00

Question 2

Calico cats are female because

Accepted Answer

A)  a male inherits only one of the two X-linked genes controlling hair color.
B)  the males die during embryonic development.
C)  the Y chromosome has a gene blocking orange coloration.
D)  only females can have Barr bodies.
E)  multiple crossovers on the Y chromosome prevent orange pigment production.

Question 3

Figure 15.4 
-The pedigree in Figure 15.4 shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely

Accepted Answer

A)  mitochondrial.
B)  autosomal recessive.
C)  sex-linked dominant.
D)  sex-linked recessive.
E)  autosomal dominant.

Question 4

Which of the following statements is True?

Accepted Answer

A)  The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.
B)  The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%.
C)  All of the traits that Mendel studied seed color, pod shape, flower color, and others are due to genes linked on the same chromosome.
D)  Linked genes are found on different chromosomes.
E)  Crossing over occurs during prophase II of meiosis.

Question 5

A 0.1% frequency of recombination is observed

Accepted Answer

A)  only in sex chromosomes.
B)  only on genetic maps of viral chromosomes.
C)  on unlinked chromosomes.
D)  in any two genes on different chromosomes.
E)  in genes located very close to one another on the same chromosome.

Question 6

D, F, and J are three genes in Drosophila. The recombination frequencies for two of the three genes are shown in Figure 15.3.
   Gene Pair  Recombination Frequency  D-F 50% D-J 25% F-J ?\begin{array} { c c } 	ext { Gene Pair } & 	ext { Recombination Frequency } \\hline 	ext { D-F } & 50 \% \	ext { D-J } & 25 \% \	ext { F-J } & ?\end{array} Gene Pair  D-F  D-J  F-J ​ Recombination Frequency 50%25%?​​

-Genes D and F could be

Accepted Answer

A)  located on different chromosomes.
B)  located very near to each other on the same chromosome.
C)  located far from each other on the same chromosome.
D)  Both A and B
E)  Both A and C

Question 7

Two genes of a flower, one controlling blue (B)versus white (b)petals and the other controlling round (R)versus oval (r)stamens, are linked and are 10 map units apart. You cross a homozygous blue-oval plant with a homozygous white-round plant. The resulting F1 progeny are crossed with homozygous white-oval plants, and 1,000 F2 progeny are obtained. How many F2 plants of each of the four phenotypes do you expect?

Accepted Answer

450 each of blue-oval and whit...

Question 8

Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?

Accepted Answer

A)    XcXc X ^{c X c} XcXc  and  XcY X^{c Y}  XcY 
B)    XcXc X^{c X c} XcXc  and  XCY X ^{C Y} XCY 
C)    XCXC X ^{C X C} XCXC  and  XcY X ^{c Y} XcY 
D)    XCXC X ^{C X C} XCXC  and  XCY X^{ C Y} XCY 
E)    XCXc X^{C X c} XCXc  and  XCY X^{C Y} XCY

Question 9

What does a frequency of recombination of 50% indicate?

Accepted Answer

A)  The two genes are likely to be located on different chromosomes.
B)  All of the offspring have combinations of traits that match one of the two parents.
C)  The genes are located on sex chromosomes.
D)  Abnormal meiosis has occurred.
E)  Independent assortment is hindered.

Question 10

A space probe discovers a planet inhabited by creatures that reproduce with the same hereditary patterns seen in humans. Three phenotypic characters are height (T = tall, t = dwarf), head appendages (A = antennae, a = no antennae), and nose morphology (S = upturned snout, s = downturned snout). Since the creatures are not "intelligent," Earth scientists are able to do some controlled breeding experiments, using various heterozygotes in testcrosses. For tall heterozygotes with antennae, the offspring are: tall-antennae, 46; dwarf-antennae, 7; dwarf-no antennae, 42; tall-no antennae, 5. For heterozygotes with antennae and an upturned snout, the offspring are: antennae-upturned snout, 47; antennae-downturned snout, 2; no antennae-downturned snout, 48; no antennae-upturned snout, 3. Calculate the recombination frequencies for both experiments.

Accepted Answer

Between T ...

Question 11

A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype?

Accepted Answer

A)  Masculine characteristics such as facial hair
B)  Enlarged genital structures
C)  Excessive emotional instability
D)  Normal female
E)  Sterile female

Question 12

If a human interphase nucleus contains three Barr bodies, it can be assumed that the person

Accepted Answer

A)  has hemophilia.
B)  is a male.
C)  has four X chromosomes.
D)  has Turner syndrome.
E)  has Down syndrome.

Question 13

At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?

Accepted Answer

A)  Early prophase
B)  Late telophase
C)  Anaphase
D)  Late anaphase or early telophase
E)  Late prophase or metaphase

Question 14

Which of the following is a map of a chromosome that includes the positions of genes relative to visible chromosomal features, such as stained bands?

Accepted Answer

A)  Linkage map
B)  Physical map
C)  Recombination map
D)  Cytogenetic map
E)  Banded map

Question 15

Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher?

Accepted Answer

A)  People in Latin or South America
B)  The Inuit and other peoples in very cold habitats
C)  People living in equatorial areas of the world
D)  Very small population groups
E)  No groups have such higher frequency

Exam 15: The Chromosomal Basis of Inheritance

A 0.1% frequency of recombination is observed

Correct Answer
verified

Correct Answer
verified

Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher?

Correct Answer
verified

A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype?

Correct Answer
verified

They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?

Correct Answer
verified

At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?

Correct Answer
verified

Correct Answer
verified
Between T ...
View Answer

Figure 15.4 -The pedigree in Figure 15.4 shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely

Correct Answer
verified

Which of the following statements is True?

Correct Answer
verified

If a human interphase nucleus contains three Barr bodies, it can be assumed that the person

Correct Answer
verified

What does a frequency of recombination of 50% indicate?

Correct Answer
verified

Which of the following is a map of a chromosome that includes the positions of genes relative to visible chromosomal features, such as stained bands?

Correct Answer
verified

Calico cats are female because

Correct Answer
verified

Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?

Correct Answer
verified

Correct Answer
verified
450 each of blue-oval and whit...
View Answer

Exam 15: The Chromosomal Basis of Inheritance

A 0.1% frequency of recombination is observed

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher?

Correct AnswerverifiedShow Answer

A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype?

Correct AnswerverifiedShow Answer

They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?

Correct AnswerverifiedShow Answer

At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedBetween T ...View AnswerShow Answer

Figure 15.4 -The pedigree in Figure 15.4 shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely

Correct AnswerverifiedShow Answer

Which of the following statements is True?

Correct AnswerverifiedShow Answer

If a human interphase nucleus contains three Barr bodies, it can be assumed that the person

Correct AnswerverifiedShow Answer

What does a frequency of recombination of 50% indicate?

Correct AnswerverifiedShow Answer

Which of the following is a map of a chromosome that includes the positions of genes relative to visible chromosomal features, such as stained bands?

Correct AnswerverifiedShow Answer

Calico cats are female because

Correct AnswerverifiedShow Answer

Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?

Correct AnswerverifiedShow Answer

Correct Answerverified450 each of blue-oval and whit...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Between T ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
450 each of blue-oval and whit...
View Answer