Question 1

The sequence-specific binding of BamHI to DNA depends primarily on
A)hydrogen bonding and allows binding to less specific sequences as well.
B)hydrogen bonding and precludes binding to any other sequence.
C)stacking interactions and could be mimicked using an intercalation molecule.
D)hydrogen bonding and could be mimicked using an intercalation molecule.
E)none of the above

Accepted Answer

The sequence-specific binding of BamHI to DNA precludes binding to any other sequence. This is because the enzyme recognizes and binds to a specific short sequence of six nucleotides known as the recognition sequence or restriction site. This binding is mediated by hydrogen bonding between specific amino acid residues in the enzyme and the nucleotide bases in the DNA. Therefore, choice A is incorrect as it suggests that BamHI can bind to less specific sequences. Choice C and D are incorrect as stacking interactions and intercalation molecules are not involved in the sequence-specific binding of BamHI to DNA.

Question 2

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-RNA catalysts are called ______.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

RNA catalysts are called ribozymes, also known as ribocatalysts or ribozymal enzymes. The correct choice is N for ribozymes.

Question 3

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Naturally occurring circular DNA is typically _______.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

M

Question 4

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Single-strand breaks in DNA are transiently created by ______ topoisomerases.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

Type I topoisomerases create single-strand breaks in DNA as a part of their mechanism to relieve tension and prevent supercoiling.

Question 5

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Heptad repeats are found in the ______ region of DNA binding proteins.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

The answer of Matching 
Choose the correct answer from the...

Question 6

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Complementary DNA and RNA strands can be ______.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

Complementary DNA and RNA strands can be hybridized, or bonded together through base pairing.

Question 7

What evidence suggests that a biological function exists for Z-DNA?
A)Z-DNA is unique because it is made up of alternating pyrimidine and purine residues in the anti and syn conformation.
B)The left-handed nature of Z-DNA allows phosphate separation which is stabilizing..
C)X-ray structure of the protein ZF1F1F1S1F1F1F10 binding Z-DNA has been identified.
D)A and B
E)A, B, and C

Accepted Answer

The answer of What evidence suggests that a biological function...

Question 8

Histone H1 binds to ____ which allows attachment to _____.
A)the nucleosome core particle; nucleases
B)linker DNA; the next nucleosome
C)the nucleosome core particle; the next nucleosome
D)linker DNA; nucleases
E)none of the above

Accepted Answer

Histone H1 binds to the linker DNA, which is the region of DNA between two nucleosomes, allowing it to attach to the next nucleosome. It does not directly bind to the nucleosome core particle or nucleases.

Question 9

Heat-denatured DNA exhibits ______ UV absorbance, which is called the ______.
A)increased; hyperchromic effect
B)decreased; hyperchromic effect
C)increased; hypochromic effect
D)decreased; hypochromic effect
E)identical; renaturation effect

Accepted Answer

Heat-denatured DNA exhibits increased UV absorbance, which is called the hyperchromic effect.

Question 10

The chromosomes of some viruses and bacteria are ______ and often ______.
A)linear; single stranded
B)linear; supercoiled
C)circular; single stranded
D)circular; supercoiled
E)none of the above

Accepted Answer

Some viruses and bacteria have circular chromosomes, which are often supercoiled to fit within the cell.

Question 11

Which of the following prokaryotic enzymes can introduce negative supercoils?
A)topoismerase IA
B)topoismerase III
C)DNA gyrase
D)all of the above
E)none of the above

Accepted Answer

DNA gyrase is the prokaryotic enzyme that can introduce negative supercoils. Topoisomerase IA and III can only introduce relaxation or nicking of DNA strands.

Question 12

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-In prokaryotes, many of the _____ that bind to DNA contain a HTH motif.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

In prokaryotes, many of the repressors that bind to DNA contain a helix-turn-helix (HTH) motif, which is a common structural motif in proteins that bind to DNA.

Question 13

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-_________ topoisomerases that make double-strand breaks in DNA in a controlled fashion.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

Type II topoisomerases make double-stranded breaks in DNA in a controlled fashion.

Question 14

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-The denaturation of DNA is a ______ cooperative process.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

The denaturation of DNA is a cooperative process, meaning that the unraveling of the double helix occurs progressively and requires the participation of multiple base pairs at a time. This is in contrast to a non-cooperative process, where each base pair would separate independently.

Question 15

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-The 2-deoxyribose groups assume the ____ conformation in B-DNA.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

The 2-deoxyribose groups in B-DNA assume the C2'-endo conformation, which means that the sugar molecule is tilted slightly away from the base pair. This conformation is important for maintaining the three-dimensional structure of the DNA double helix.

Question 16

Which of the following scientists is now accredited with generating the X-ray diffraction photograph that played a pivotal role in the discovery of the structure of B-DNA?
A)James Watson
B)Francis Crick
C)Maurice Wilkins
D)Rosalind Franklin
E)all of the above

Accepted Answer

Rosalind Franklin is credited with generating the X-ray diffraction photograph, known as Photo 51, which provided crucial evidence for the double helix structure of DNA. James Watson and Francis Crick used this photograph as key evidence in their model of DNA. Maurice Wilkins also contributed to the discovery of the structure of DNA, but he did not generate Photo 51.

Question 17

Which of the following would NOT result in the relaxation of supercoiled DNA?
A)heating the DNA to induce denaturation
B)nicking one strand
C)treatment with pancreatic DNaseI
D)treatment with type II topoisomerase
E)treatment with type I topoisomerase

Accepted Answer

Heating the DNA to induce denaturation would result in the separation of the two strands of DNA, but would not affect the supercoiled structure. The other choices involve enzymes that can relieve supercoiling by breaking and rejoining DNA strands.

Question 18

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-________, an ion that intercalates into double-stranded DNA, is often used for staining gels.
A)type I
B)ribocatalyzers
C)C2'-endo
D)repressors
E)ethidium
F)type II
G)C3'-endo
H)hybridized
I)interchanged
J)supercoiled
K)cooperative
L)non-cooperative
M)underwound
N)ribozymes
O)deuterium
P)zinc finger
Q)leucine zipper

Accepted Answer

Ethidium is a fluorescent dye commonly used to stain nucleic acids in gels, and it intercalates into the double-stranded DNA molecule, causing it to fluoresce in the presence of UV light.

Question 19

Which of the following materials would be useful for a researcher seeking to purify chromosomal DNA of lysed E.coli cells from cellular proteins and RNA?
A)ethidium bromide
B)hydroxyapatite
C)acridine orange
D)proflavin
E)DNA gyrase

Accepted Answer

Hydroxyapatite is a common material used for chromatographic separation of DNA from RNA and protein.

Question 20

tRNA molecules are
I.extensively base-paired.
II.stabilized by hydrogen bonds.
III.stabilized by stacking interactions.
IV.stabilized by covalent cross links.
A)I, II
B)II, III
C)I, II, III
D)I, III
E)I, II, IV

Accepted Answer

tRNA molecules are extensively base-paired, forming a cloverleaf structure that is stabilized by hydrogen bonds between complementary bases. Additionally, stacking interactions between adjacent bases contribute to the stability of the tRNA structure. There are no covalent cross-links stabilizing tRNA molecules.

Quiz 24: Nucleic Acid Structure

The sequence-specific binding of BamHI to DNA depends primarily on

Matching Choose the correct answer from the list. Not all the answers will be used. -RNA catalysts are called ______.

Matching Choose the correct answer from the list. Not all the answers will be used. -Naturally occurring circular DNA is typically _______.

Matching Choose the correct answer from the list. Not all the answers will be used. -Single-strand breaks in DNA are transiently created by ______ topoisomerases.

Matching Choose the correct answer from the list. Not all the answers will be used. -Heptad repeats are found in the ______ region of DNA binding proteins.

Matching Choose the correct answer from the list. Not all the answers will be used. -Complementary DNA and RNA strands can be ______.

What evidence suggests that a biological function exists for Z-DNA?

Histone H1 binds to which allows attachment to _.

Heat-denatured DNA exhibits UV absorbance, which is called the .

The chromosomes of some viruses and bacteria are and often .

Which of the following prokaryotic enzymes can introduce negative supercoils?

Matching Choose the correct answer from the list. Not all the answers will be used. -In prokaryotes, many of the _____ that bind to DNA contain a HTH motif.

Matching Choose the correct answer from the list. Not all the answers will be used. -_________ topoisomerases that make double-strand breaks in DNA in a controlled fashion.

Matching Choose the correct answer from the list. Not all the answers will be used. -The denaturation of DNA is a ______ cooperative process.

Matching Choose the correct answer from the list. Not all the answers will be used. -The 2-deoxyribose groups assume the ____ conformation in B-DNA.

Which of the following scientists is now accredited with generating the X-ray diffraction photograph that played a pivotal role in the discovery of the structure of B-DNA?

Which of the following would NOT result in the relaxation of supercoiled DNA?

Matching Choose the correct answer from the list. Not all the answers will be used. -________, an ion that intercalates into double-stranded DNA, is often used for staining gels.

Which of the following materials would be useful for a researcher seeking to purify chromosomal DNA of lysed E.coli cells from cellular proteins and RNA?

tRNA molecules are I.extensively base-paired. II.stabilized by hydrogen bonds. III.stabilized by stacking interactions. IV.stabilized by covalent cross links.