Name: 
 

Chapter 19 Review



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

 1. 

Which of the following statements concerning the eukaryotic chromosome is false?
a.
It is composed of DNA and protein.
b.
The nucleosome is the most basic structural subunit.
c.
The number of genes on each chromosome is different in different cell types.
d.
It consists of a single linear molecule of double-stranded DNA.
e.
Active transcription occurs on euchromatin.
 

 2. 

Which of the following statements about histones is incorrect?
a.
Each nucleosome consists of two molecules, each of four types of histone.
b.
Histone H1 is not present in the nucleosome bead; instead it is involved in the formation of higher-level chromatin structures.
c.
The amino 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 equal to the mass of DNA.
 

 3. 

Muscle cells and nerve cells in one species of animal owe their differences in structure to
a.
having different genes.
b.
having different chromosomes.
c.
using different genetic codes.
d.
differential gene expression.
e.
having unique ribosomes.
 

 4. 

Which of the following mechanisms is (are) used to coordinately control the expression of multiple, related genes in eukaryotic cells?
a.
organization of the genes into clusters, with local chromatin structures influencing the expression of all the genes at once
b.
each of the genes sharing a common control element, allowing a single activator to turn on their transcription at once, regardless of their location in the genome
c.
organizing the genes into large operons, allowing them to be transcribed as a single unit
d.
A and B only
e.
A, B, and C
 

 5. 

Two potential devices that eukaryotic cells use to regulate transcription are DNA ____ and histone ____.
a.
methylation; amplification
b.
amplification; methylation
c.
acetylation; methylation
d.
methylation; acetylation
e.
amplification; acetylation
 

 6. 

A significant difference between eukaryotes and prokaryotes is that
a.
DNA is wound around proteins to form chromatin in eukaryotes, but in prokaryotes the DNA is not associated with proteins.
b.
gene expression is largely regulated by transcription in prokaryotes, but not in eukaryotes.
c.
prokaryotic genes do not contain introns.
d.
noncoding DNA sequences are found in prokaryotes, but not in eukaryotes.
e.
prokaryotes have less DNA but more noncoding segments than eukaryotes.
 
 
Use the terms below to answer the following questions. Each term may be used once, more than once, or not at all.

A. enhancer
B. promoter
C. activator
D. repressor
E. terminator
 

 7. 

binds to a site in the DNA far from the promoter to stimulate transcription
a.
A
b.
B
c.
C
d.
D
e.
E
 

 8. 

can inhibit transcription by blocking the binding of positively acting transcription factors to the DNA
a.
A
b.
B
c.
C
d.
D
e.
E
 

 9. 

Which of the following is least related to the others?
a.
cyclins
b.
ubiquitin
c.
tumor suppression
d.
protein degradation
e.
proteasomes
 

 10. 

The incidence of cancer increases dramatically with age because
a.
the Ras protein is more likely to be hyperactive after age sixty.
b.
proteasomes become more active with age.
c.
as we age, normal cell division inhibitors cease to function.
d.
the longer we live, the more mutations accumulate.
e.
tumor-suppressor genes are no longer able to repair damaged DNA.
 

 11. 

Which of the following statements concerning transposons is false?
a.
Transposons may increase the production of a particular protein.
b.
Transposons may prevent the normal functioning of a gene.
c.
Transposons may decrease the production of a particular protein.
d.
Transposons may reduce the amount of DNA within certain cells.
e.
Both A and C are false.
 

 12. 

In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. This is due to
a.
nonidentical genes that produce different versions of globins during development.
b.
identical genes that generate many copies of the ribosomes needed for fetal globin production.
c.
pseudogenes, which interfere with gene expression in adults.
d.
the attachment of methyl groups to cytosine following birth, which changes the type of hemoglobin produced.
e.
histone proteins changing shape during embryonic development.
 

 13. 

What do pseudogenes and introns have in common?
a.
They code for RNA end products, rather than proteins.
b.
They both contain uracil.
c.
They have multiple promoter sites.
d.
They both code for histones.
e.
They are not expressed, nor do they code for functional proteins.
 

 14. 

Scientists often deduce the evolutionary history of the different members of a gene family by
a.
comparing the sequences of the genes.
b.
determining which of the genes are mutated in human diseases.
c.
comparing the relative enzymatic activities of the proteins encoded by the genes.
d.
overexpressing each of the genes in a cell and determining which has the most destructive effect.
e.
examining the relative stability of the mRNAs produced from the genes.
 



 
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