Bio1306 Exam 4 Practice 50 Questions with Verified Answers
The final product produced from the "Central Dogma Theory" is ___
a) mRNA
b) DNA
c)
... [Show More] absolutely nothing
d) proteins - CORRECT ANSWER d) proteins
How is DNA replicated?
a) it's too small to tell
b) semi-conservative replication
c) dispersive replication
d) conservative replication - CORRECT ANSWER b) semi-conservative replication
DNA polymerase perform what function?
a) synthesizes a growing strand of RNA
b) synthesizes a growing strand of DNA
c) reduces the amount of polymers in DNA
d) produces polymers in DNA - CORRECT ANSWER b) synthesizes a growing strand of DNA
DNA helicases are important in DNA synthesis because they
a) break hydrogen bonds between two complementary DNA strands
b) relieve the tension as the DNA strand is uncoiled
c) places a free 3'-OH group on a newly formed DNA strand
d) combine two DNA strands together - CORRECT ANSWER a) break hydrogen bonds between two complementary DNA strands
Primers are required for DNA synthesis because they?
a) supply the free 3'-OH group for the addition of the first nucleotide
b) it's not needed in DNA synthesis
c) remove nucleotides from newly formed DNA strands
d) proofread the newly synthesized DNA strand for errors - CORRECT ANSWER
Transcription is an important step in producing proteins because
a) produces proteins from amino acids
b) it converts DNA sequences into mRNA
c) it allows RNA to be converted in DNA
d) prepares RNA to be converted into amino acids - CORRECT ANSWER b) it converts DNA sequences into mRNA
What is the function of DNA primase?
a) closing the gap at 3' end of DNA after excision repair
b) removing primers and synthesizing a short section of DNA to replace them
c) synthesis of the short section of double-stranded DNA required by DNA polymerase
d) synthesis of a short section of RNA, complementary to single-stranded DNA - CORRECT ANSWER d) synthesis of a short section of RNA, complementary to single-stranded DNA
A promoter serves which function?
a) it specifies where RNA polymerase binds to initiate transcription
b) catalyzes the acetylation and methylation of histones
c) condenses chromatin to fit inside the nucleus
d) controlling the activity of genes - CORRECT ANSWER a) it specifies where RNA polymerase binds to initiate transcription
What is the function of topoisomerase?
a) opening the DNA helix at the replication fork
b) holding DNA polymerase steady as it moves down the leading or lagging strand
c) stabilizing single strands of DNA, once the replication fork is open
d) preventing kinks in DNA as the replication fork opens and unwinds - CORRECT ANSWER d) preventing kinks in DNA as the replication fork opens and unwinds
Where and how are Okazaki fragments synthesized?
a) on the leading strand, in a 3' to 5' direction
b) on the lagging strand, in a 5' to 3' direction
c) on the leading strand, in a 5' to 3' direction
d) on the lagging strand, in a 3' to 5' direction - CORRECT ANSWER b) on the lagging strand, in a 5' to 3' direction
How does cellular information flow in viruses that utilize reverse transcriptase? - CORRECT ANSWER RNA, DNA, RNA, proteins
A primary RNA transcript molecule will contain:
a) intons
b) introns and exons
c) exons
d) DNA - CORRECT ANSWER b) introns and exons
After a mature RNA is produced, what must be added to the RNA strand before it is transported out of the nucleus?
a) 5' cap
b) poly(A) tail
c) introns
d) both A and B - CORRECT ANSWER d) both A and B
Which of the following codons is the start codon(s)?
a) UGA
b) UAA
c) AUG
d) all of the above - CORRECT ANSWER c) AUG
What is meant by the description "antiparallel" regarding the strands that make up DNA?
a) base pairings create unequal spacing between the two DNA strands
b) the twisting nature of DNA creates nonparallel strands
c) one strands contains only purines and the other contains only pyrimidines
d) the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand - CORRECT ANSWER d) the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand
What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
a) it synthesizes RNA nucleotides to make a primer
b) it unwinds the parental double helix
c) it joins Okazaki fragments together
d) it stabilizes the unwound parental DNA - CORRECT ANSWER c) it joins Okazaki fragments together
Which of the following help(s) to hold the DNA strands apart while they are being replicated?
a) ligase
b) DNA polymerase
c) primase
d) single-stranded DNA binding proteins - CORRECT ANSWER d) single-stranded DNA binding proteins
Semiconservative replication involves a template. What is the template?
a) DNA polymerase
b) an RNA molecule
c) one strand of the DNA molecule
d) single-stranded binding proteins - CORRECT ANSWER c) one strand of the DNA molecule
A particular triplet of bases in the template strand of DNA is 5'-AGT-3'. The corresponding codon for the mRNA transcribed is ___
a) 3'-UGA-5'
b) 3'-ACU-5'
c) 3'-UCA-5'
d) 5'-TCA-3' - CORRECT ANSWER c) 3'-UCA-5'
In the process of transcription, ___
a) mRNA attaches to ribosomes
b) DNA is replicated
c) protein is synthesized
d) RNA is transcripted - CORRECT ANSWER d) RNA is transcripted
Which of the following, is missing, would usually prevent translation from starting?
a) exon
b) poly-A tail
c) 5' cap
d) AUG codon - CORRECT ANSWER d) AUG codon
How does termination of translation take place?
a) the poly-A tail is reached
b) a stop codon is reached
c) the end of the mRNA molecule is reached
d) the 5' cap is reached - CORRECT ANSWER b) a stop codon is reached
A nonsense mutation in a gene ___
a) changes an amino acid in the encoded protein
b) has no effect on the amino acid sequence of the encoded protein
c) introduces a premature stop codon into the mRNA
d) makes the organism lose its' sense of humor - CORRECT ANSWER c) introduces a premature stop codon into the mRNA
The accepted hypothesis for DNA replication is
a) conservative theory
b) dispersive theory
c) semi-conservative theory
d) evolutionary theory - CORRECT ANSWER c) semi-conservative theory
When DNA polymerase is in contact with guanine in the parental strand, what does it add to the growing daughter strand?
a) phosphate
b) cytosine
c) uracil
d) guanine - CORRECT ANSWER b) cytosine
In DNA double helix, the two DNA chains are held together by:
a) covalent bonds between the pair of bases
b) hydrogen bonds between the pair of bases
c) ionic bonds between the pair of bases
d) none of the above - CORRECT ANSWER b) hydrogen bonds between the pair of bases
The 5' to 3' numbers are related to the:
a) length of the DNA strand
b) carbon number in sugar
c) the number of phosphates
d) the base pair rule - CORRECT ANSWER b) carbon number in sugar
DNA replication takes place in which direction?
a) 3' to 5'
b) 5' to 3'
c) randomly
d) vary from organism to organism - CORRECT ANSWER b) 5' to 3'
In DNA, there are:
a) five bases known as adenine, guanine, thymine, tryptophan, and cytosine
b) four bases known as adenine, guanine, thymine, and cytosine
c) three bases known as adenine, guanine, and cytosine
d) only two bases known as adenine and cytosine - CORRECT ANSWER b) four bases known as adenine, guanine, thymine, and cytosine
In DNA, guanine pairs with
a) adenine
b) cytosine
c) thymine
d) uracil - CORRECT ANSWER b) cytosine
Which of the following enzyme adds complementary bases during replication?
a) helicase
b) DNA synthesis
c) DNA replicase
d) DNA polymerase - CORRECT ANSWER d) DNA polymerase
Enzymes involved in opening a replication bubble are
a) DNA helicases
b) single-stranded binding proteins
c) ligase
d) DNA topoisomerase - CORRECT ANSWER a) DNA helicases
Okazaki fragments occur during
a) transformation
b) replication
c) polymerase reaction
d) synthesis - CORRECT ANSWER b) replication
What term is used to describe the process by which a segment of DNA is copied to produce a molecule of messenger RNA?
a) reproduction
b) replication
c) translation
d) transcription - CORRECT ANSWER d) transcription
What term is used to describe the process by which proteins by which proteins are synthesized from a genetic code?
a) reproduction
b) replication
c) translation
d) transcription - CORRECT ANSWER c) translation
Amino acids are joined together in order to form
a) DNA
b) proteins
c) ribosomes
d) RNA - CORRECT ANSWER b) proteins
What is the function of mRNA?
a) storage of food
b) provides energy
c) prevents mutations
d) carries genetic messages - CORRECT ANSWER d) carries genetic messages
The DNA sequence ATCAGCGCTGGC is part of a gene. How many amino acids are coded for by this message?
a) 20
b) 12
c) 8
d) 4 - CORRECT ANSWER b) 12
Codons contain ___ bases.
a) 1
b) 3
c) 6
d) 9 - CORRECT ANSWER b) 3
What is the name of 3 bases on mRNA called?
a) gene
b) triplet
c) codon
d) anticodon - CORRECT ANSWER c) codon
The ends of the linear chromosomes are maintained by
a) telomerase
b) DNA pol
c) helicase
d) primase - CORRECT ANSWER a) telomerase
Dr. Rosalind Franklin's research determined ___
a) the B-form of DNA helix
b) the purines and pyrimidines are always paired together
c) phosphate groups are on the outside of the DNA structure
d) all of the above - CORRECT ANSWER d) all of the above
If the sequence of the 5'-3' strand is AATGCTAC, then the complementary sequence has the following sequence: - CORRECT ANSWER 3'-TTACGATG-5'
Which of the following components is not involved during the formation of the replication fork?
a) ligase
b) origin of replication
c) single-stranded binding proteins
d) helicase - CORRECT ANSWER a) ligase
The initial mechanism for repairing nucleotide errors in DNA is ________.
a) DNA polymerase proofreading
b) mismatch repair
c) thymine dimers
d) nucleotide excision repair - CORRECT ANSWER a) DNA polymerase proofreading
Which of the following does the enzyme primase synthesize?
a) phosphodiester linkage
b) Okazaki fragments
c) DNA primer
d) RNA primer - CORRECT ANSWER d) RNA primer
How many nucleotides are in 12 mRNA codons?
a) 12
b) 36
c) 24
d) 48 - CORRECT ANSWER b) 36
In eukaryotes, what is the DNA wrapped around?
a) sliding chain
b) single-stranded binding proteins
c) histones
d) polymerase - CORRECT ANSWER c) histones
DNA double helix does not have which of the following?
a) major and minor grooves
b) uracil
c) antiparallel configuration
d) complementary base pairing - CORRECT ANSWER b) uracil
Which event contradicts the central dogma of molecular biology?
a) poly-A polymerase enzymes process mRNA in the nucleus
b) endonuclease enzymes splice out and repair damaged DNA
c) scientists use reverse transcriptase enzymes to make DNA from RNA
d) codons specifying amino acids are degenerate and universal - CORRECT ANSWER c) scientists use reverse transcriptase enzymes to make DNA from RNA [Show Less]