Genetics Final Exam Questions With
Correct Answers | Updated
/Viral chromosomes exist in a variety of conformations and can be made up of
________.
A) protein- or lipid-coding sequences
B) DNA only
C) DNA or RNA
D) RNA only
E) DNA, RNA, or protein - Answer-C) DNA or RNA
/.In E. coli, the genetic material is composed of ________.
A) circular, double-stranded DNA
B) linear, double-stranded DNA
C) RNA and protein
D) circular, double-stranded RNA
E) polypeptide chains - Answer-A) circular, double-stranded DNA
/.Eukaryotic chromosomes contain two general domains that relate to the degree of
condensation. These two regions are ________.
A) called heterochromatin and euchromatin
B) uniform in the genetic information they contain
C) separated by large stretches of repetitive DNA
D) each void of typical protein-coding sequences of DNA
E) void of introns - Answer-A) called heterochromatin and euchromatin
/.Chromatin of eukaryotes is organized into repeating interactions with protein octomers
called nucleosomes. Nucleosomes are composed of which class of molecules?
A) histones
B) glycoproteins
C) lipids
D) H1 histones
E) nonhistone chromosomal proteins - Answer-A) histones
/.That some organisms contain much larger amounts of DNA than are apparently
"needed" and that other relatively closely related organisms may have vastly different
amounts of DNA is more typical in ________.
A) viruses than in bacteria
B) RNA viruses than in DNA viruses
C) eukaryotes than in prokaryotes
D) the alphoid rather than the diphloid family
E) prokaryotes than in eukaryotes - Answer-C) eukaryotes than in prokaryotes
, /.In addition to highly repetitive and unique DNA sequences, a third category of DNA
sequences exists. What is it called, and which types of elements are involved in it?
A) composite DNA; telomeres and heterochromatin
B) dominant DNA; euchromatin and heterochromatin
C) multiple gene family DNA; hemoglobin and 5.0S RNA
D) moderately repetitive DNA; SINEs, LINEs, and VNTRs
E) permissive DNA; centromeres and heterochromatin - Answer-D) moderately
repetitive DNA; SINEs, LINEs, and VNTRs
/.List several configurations that characterize different viral chromosomes. - Answer-
DNA (single- and double-stranded),
RNA (single- and double-stranded),
linear,
circular
/.Although mutations have been observed in many different genes, they have not been
isolated in histones. Why does this seem reasonable? If one wanted to produce
antibodies to histones, would it be an easy task? Explain your answer. - Answer-
Histones represent one of the most conserved molecules in nature because they are
involved in a fundamental and important function relating to chromosome structure.
Mutations are probably lethal. Because all antibody-producing organisms have
essentially the same histones, it would be difficult to find an organism that produces
histone antibodies, for to do so would be self-destructive.
/.What is unusual about the amino acid composition of histones? How is the function of
histones related to the amino acid composition? Of which histones are nucleosomes
composed? - Answer-Histones contain large amounts of positively charged amino acids
such as lysine and arginine. Thus, they can bind electrostatically to the negatively
charged phosphate groups of nucleotides. Nucleosomes are composed of all histones
except H1.
/.Describe the basic structure of a nucleosome. What is the role of histone H1? -
Answer-Nucleosomes are composed of four different histone molecules, each of which
exists twice, thus forming an octomer. Histone H1 is between nucleosomes and is
associated with linker DNA.
/.Compare and contrast the chromosome structure of viruses, bacteria, and eukaryotes.
- Answer-The amount of DNA per structure (virus particle, bacterium, cell) increases as
one goes from viruses to eukaryotic cells. Viral chromosomes may be composed of
single-stranded or double-stranded RNA or DNA, whereas bacterial and eukaryotic
DNA is double-stranded. Bacterial DNA is considered to be a covalently closed circle;
the "global" structure of eukaryotic chromosomes is uncertain. Although some proteins
are associated with viral and bacterial DNA, the regularly spaced histones of eukaryotic
chromosomes are unique.
Correct Answers | Updated
/Viral chromosomes exist in a variety of conformations and can be made up of
________.
A) protein- or lipid-coding sequences
B) DNA only
C) DNA or RNA
D) RNA only
E) DNA, RNA, or protein - Answer-C) DNA or RNA
/.In E. coli, the genetic material is composed of ________.
A) circular, double-stranded DNA
B) linear, double-stranded DNA
C) RNA and protein
D) circular, double-stranded RNA
E) polypeptide chains - Answer-A) circular, double-stranded DNA
/.Eukaryotic chromosomes contain two general domains that relate to the degree of
condensation. These two regions are ________.
A) called heterochromatin and euchromatin
B) uniform in the genetic information they contain
C) separated by large stretches of repetitive DNA
D) each void of typical protein-coding sequences of DNA
E) void of introns - Answer-A) called heterochromatin and euchromatin
/.Chromatin of eukaryotes is organized into repeating interactions with protein octomers
called nucleosomes. Nucleosomes are composed of which class of molecules?
A) histones
B) glycoproteins
C) lipids
D) H1 histones
E) nonhistone chromosomal proteins - Answer-A) histones
/.That some organisms contain much larger amounts of DNA than are apparently
"needed" and that other relatively closely related organisms may have vastly different
amounts of DNA is more typical in ________.
A) viruses than in bacteria
B) RNA viruses than in DNA viruses
C) eukaryotes than in prokaryotes
D) the alphoid rather than the diphloid family
E) prokaryotes than in eukaryotes - Answer-C) eukaryotes than in prokaryotes
, /.In addition to highly repetitive and unique DNA sequences, a third category of DNA
sequences exists. What is it called, and which types of elements are involved in it?
A) composite DNA; telomeres and heterochromatin
B) dominant DNA; euchromatin and heterochromatin
C) multiple gene family DNA; hemoglobin and 5.0S RNA
D) moderately repetitive DNA; SINEs, LINEs, and VNTRs
E) permissive DNA; centromeres and heterochromatin - Answer-D) moderately
repetitive DNA; SINEs, LINEs, and VNTRs
/.List several configurations that characterize different viral chromosomes. - Answer-
DNA (single- and double-stranded),
RNA (single- and double-stranded),
linear,
circular
/.Although mutations have been observed in many different genes, they have not been
isolated in histones. Why does this seem reasonable? If one wanted to produce
antibodies to histones, would it be an easy task? Explain your answer. - Answer-
Histones represent one of the most conserved molecules in nature because they are
involved in a fundamental and important function relating to chromosome structure.
Mutations are probably lethal. Because all antibody-producing organisms have
essentially the same histones, it would be difficult to find an organism that produces
histone antibodies, for to do so would be self-destructive.
/.What is unusual about the amino acid composition of histones? How is the function of
histones related to the amino acid composition? Of which histones are nucleosomes
composed? - Answer-Histones contain large amounts of positively charged amino acids
such as lysine and arginine. Thus, they can bind electrostatically to the negatively
charged phosphate groups of nucleotides. Nucleosomes are composed of all histones
except H1.
/.Describe the basic structure of a nucleosome. What is the role of histone H1? -
Answer-Nucleosomes are composed of four different histone molecules, each of which
exists twice, thus forming an octomer. Histone H1 is between nucleosomes and is
associated with linker DNA.
/.Compare and contrast the chromosome structure of viruses, bacteria, and eukaryotes.
- Answer-The amount of DNA per structure (virus particle, bacterium, cell) increases as
one goes from viruses to eukaryotic cells. Viral chromosomes may be composed of
single-stranded or double-stranded RNA or DNA, whereas bacterial and eukaryotic
DNA is double-stranded. Bacterial DNA is considered to be a covalently closed circle;
the "global" structure of eukaryotic chromosomes is uncertain. Although some proteins
are associated with viral and bacterial DNA, the regularly spaced histones of eukaryotic
chromosomes are unique.
