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AP Biology Test Chapter 15, 16



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

The enzyme telomerase solves the problem of replication at the ends of linear chromosomes by which method?
a.
adding a single 5' cap structure that resists degradation by nucleases
b.
causing specific double strand DNA breaks that result in blunt ends on both strands
c.
causing linear ends of the newly replicated DNA to circularize
d.
adding numerous short DNA sequences such as TTAGGG, which form a hairpin turn
e.
adding numerous GC pairs which resist hydrolysis and maintain chromosome integrity
 

 2. 

A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype?
a.
Masculine characteristics such as facial hair
b.
Enlarged genital structures
c.
Excessive emotional instability
d.
Normal female
e.
Sterile female
 

 3. 

Sex determination in mammals is due to the SRY region of the Y chromosome. An abnormality could allow which of the following to have a male phenotype?
a.
Turner syndrome, 45, X
b.
Translocation of SRY to an autosome of a 46, XX individual
c.
A person with too many X chromosomes
d.
A person with one normal and one shortened (deleted) X
e.
Down syndrome, 46, XX
 

 4. 

New combinations of linked genes are due to which of the following?
a.
Nondisjunction
b.
Crossing over
c.
Independent assortment
d.
Mixing of sperm and egg
e.
Deletions
 

 5. 

The following is a map of four genes on a chromosome:

mc005-1.jpg
Figure 15.1

Between which two genes would you expect the highest frequency of recombination?
a.
A and W
b.
W and E
c.
E and G
d.
A and E
e.
A and G
 

 6. 

What is the mechanism for the production of genetic recombinants?
a.
X inactivation
b.
Methylation of cytosine
c.
Crossing over and independent assortment
d.
Nondisjunction
e.
Deletions and duplications during meiosis
 

 7. 

If a human interphase nucleus contains three Barr bodies, it can be assumed that the person
a.
has hemophilia.
b.
is a male.
c.
has four X chromosomes.
d.
has Turner syndrome.
e.
has Down syndrome.
 

 8. 

A nonreciprocal crossover causes which of the following products?
a.
Deletion only
b.
Duplication only
c.
Nondisjunction
d.
Deletion and duplication
e.
Duplication and nondisjunction
 

 9. 

What is the source of the extra chromosome 21 in an individual with Down syndrome?
a.
Nondisjunction in the mother only
b.
Nondisjunction in the father only
c.
Duplication of the chromosome
d.
Nondisjunction or translocation in either parent
e.
It is impossible to detect with current technology
 

 10. 

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?
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
 

 11. 

The following scientists made significant contributions to our understanding of the structure and function of DNA. Place the scientists' names in the correct chronological order, starting with the first scientist(s) to make a contribution.
I. Avery, McCarty, and MacLeod
II. Griffith
III. Hershey and Chase
IV. Meselson and Stahl
V. Watson and Crick
a.
V, IV, II, I, III
b.
II, I, III, V, IV
c.
I, II, III, V, IV
d.
I, II, V, IV, III
e.
II, III, IV, V, I
 

 12. 

After mixing a heat-killed, phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. Which observations would provide the best evidence that the ability to fluoresce is a heritable trait?
a.
DNA passed from the heat-killed strain to the living strain.
b.
Protein passed from the heat-killed strain to the living strain.
c.
The phosphorescence in the living strain is especially bright.
d.
Descendants of the living cells are also phosphorescent.
e.
Both DNA and protein passed from the heat-killed strain to the living strain.
 

 13. 

When T2 phages infect bacteria and make more viruses in the presence of radioactive sulfur, what is the result?
a.
The viral DNA will be radioactive.
b.
The viral proteins will be radioactive.
c.
The bacterial DNA will be radioactive.
d.
both A and B
e.
both A and C
 

 14. 

Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that
a.
the relative proportion of each of the four bases differs within individuals of a species.
b.
the human genome is more complex than that of other species.
c.
the amount of A is always equivalent to T, and C to G.
d.
the amount of ribose is always equivalent to deoxyribose.
e.
transformation causes protein to be brought into the cell.
 

 15. 

Why does the DNA double helix have a uniform diameter?
a.
Purines pair with pyrimidines.
b.
C nucleotides pair with A nucleotides.
c.
Deoxyribose sugars bind with ribose sugars.
d.
Nucleotides bind with nucleosides.
e.
Nucleotides bind with nucleoside triphosphates.
 

 16. 

In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin. Which of the following would you expect as a result of this mutation?
a.
No proofreading will occur.
b.
No replication fork will be formed.
c.
The DNA will supercoil.
d.
Replication will occur via RNA polymerase alone.
e.
Replication will require a DNA template from another source.
 

 17. 

What is the function of DNA polymerase III?
a.
to unwind the DNA helix during replication
b.
to seal together the broken ends of DNA strands
c.
to add nucleotides to the end of a growing DNA strand
d.
to degrade damaged DNA molecules
e.
to rejoin the two DNA strands (one new and one old) after replication
 

 18. 

Which of the following covalently connects segments of DNA?
a.
helicase
b.
DNA polymerase III
c.
ligase
d.
DNA polymerase I
e.
primase
 

 19. 

Which of the following help to hold the DNA strands apart while they are being replicated?
a.
primase
b.
ligase
c.
DNA polymerase
d.
single-strand binding proteins
e.
exonuclease
 

 20. 

Which would you expect of a eukaryotic cell lacking telomerase?
a.
a high probability of becoming cancerous
b.
production of Okazaki fragments
c.
inability to repair thymine dimers
d.
a reduction in chromosome length
e.
high sensitivity to sunlight
 

 21. 

Which of the following statements describes histones?
a.
Each nucleosome consists of two molecules of histone H1.
b.
Histone H1 is not present in the nucleosome bead; instead it is involved in the formation of higher-level chromatin structures.
c.
The carboxyl end of each histone extends outward from the nucleosome and is called a "histone tail."
d.
Histones are found in mammals, but not in other animals or in plants.
e.
The mass of histone in chromatin is approximately nine times the mass of DNA.
 

Short Answer
 

 22. 

A man with hemophilia (a recessive, sex-linked condition) has a daughter of normal phenotype. She marries a man who is normal for the trait. What is the probability that a daughter of this mating will be a hemophiliac? That a son will be a hemophiliac? If the couple has four sons, what is the probability that all four will be born with hemophilia?
 



 
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