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WorksheetsBIOL 101 Practice Final
Total questions: 40
Worksheet time: 23mins
In the double-stranded model of DNA structure
The 5' ends of both strands are at the same end of the helix.
A purine in one strand always hydrogen bonds with a purine in the other strand
The bases (A, T, C, and G) occupy the interior of the helix
G on one strand pairs to a C on the other strand through two hydrogen bonds
The base pairing rules for DNA state that
A = T and G = C in any molecule of DNA.
A = C and G = T in any molecule of DNA
A = G and C = T in any molecule of DNA
A = U and G = C in any molecule of RNA
DNA and RNA are made up of the same four nitrogenous bases.
The strands that make up DNA are antiparallel. This means that
one strand is positively charged, and the other is negatively charged
the base pairings create unequal spacing between the two DNA strands
the 5'-to-3' direction of one strand is counter to the 5'-to-3' direction of the other strand.
the twisting of the DNA molecule has shifted the two strands
purines bond with purines and pyrimidines bond with pyrimidines
Semiconservative replication of DNA involves
each of the original strands acting as a template for a new strand
only one of the original strands acting as a template for a new strand
the complete separation of the original strands, the synthesis of new strands, and the reassembly of the original double-stranded molecules
the use of the intact double-stranded molecule as a template.
None of the above
During replication, the new DNA strand is synthesized
in the 3'-to-5' direction
in the 5'-3' direction
in both the 3'-to-5' and 5'-to-3' directions from the replication fork
from one end to the other, in the 3'-to-5' or the 5'-to-3' direction.
none of the above
Why is RNA incorporated into the DNA molecule during DNA replication?
To keep the unwound template DNA strands from winding back up
To relieve the overwinding tension ahead of the replication fork
Because RNA primase unwinds the double-stranded DNA template.
Because DNA polymerases can only add on to an existing strand
Which diagram shows conservative replication?
A
B
Which diagram depicts the usual process of DNA replication?
A
B
Which label corresponds to a phosphate group?
A
B
C
D
E
Which label corresponds to a deoxyribose sugar?
B
A
C
D
E
Which label corresponds to a 3' end?
A
B
C
D
E
The enzyme that restores the phosphodiester linkage between adjacent fragments in the lagging strand during DNA replication is
primase
telomerase
DNA ligase
helicase
DNA polymerase III.
Which of the following is not used for DNA synthesis?
DNA polymerase I
DNA polymerase III
snRNPs in spliceosomes
RNA primase
Single-strand binding proteins
Complete the following sentence about the figure shown here: The template strand is on the _______, and _______ will be added next to the _______ end of the growing strand
right; dGTP; 3'
right; dGTP; 5'
right; dCTP; 3'
left; dCTP; 5'
left; dTTP; 3'
The enzyme that unwinds the DNA double strands during DNA replication is
primase
telomerase
DNA ligase
helicase
DNA polymerase III.
The enzyme that adds nucleotides to the growing daughter stand during DNA replication is
primase
telomerase
DNA ligase
helicase
DNA polymerase III
Which of the following is not required for transcription?
A DNA template
RNA polymerase
DNA polymerase III
Appropriate nucleoside triphosphates
RNA polymerase uses the _______ DNA template to synthesize a _______ mRNA
5'-to-3'; 5'-to-3'
3'-to-5'; 3'-to-5'
5'-to-3'; 3'-to-5'
3'-to-5'; 5'-to-3'
Examples of all of the above have been found
RNA polymerase differs from DNA polymerase in that RNA polymerase
does not require a primer
requires a primer
synthesizes in the 3’-to-5’ direction
functions in the cytosol, while DNA polymerase functions in the nucleus
functions in the cytosol, while DNA polymerase functions in the nucleus
promoter
poly C center
enhancer
operator site
primer
In eukaryotes, which of the following helps to protect newly transcribed mRNA from degradation bynucleases?
spliceosomes
a poly-A tail
a 5' cap consisting of a modified GTP
Transcription continues until
a terminator sequence is encountered.
all bases in the DNA are copied
a series of Ts in the template strand is encountered, which codes for a poly-A tail in the RNA
a stop codon is encountered
a ribosome pulls RNA polymerase off the DNA
In eukaryotes, transcription occurs in
the plasma membrane
a lysosome
the nucleus
the cytosol
the Golgi apparatus
Suppose that the coding region of a gene contains 1,800 base pairs, with 570 in exon 1,420 in exon 2, and 810 in exon 3.The length of the protein translated from this gene is _______ amino acids
190
570
600
810
1,800
Which of the following statements about pre-mRNA splicing is false?
It occurs in the nucleus
It removes introns
It is performed by small nuclear ribonucleoprotein particles (snRNPs)
It shortens the RNA molecule
It is common in prokaryotes
During translation, the formation of a peptide bond between an amino acid at the P site and an amino acid at the A site is catalyzed by
the rRNA in the large ribosomal subunit
a specialized segment of DNA
The rRNA in the small ribosomal subunit
the small proteins that are part of the ribosome structure
Stop codons terminate translation
by means of peptidyl transferase activity
by binding a protein release factor, causing hydrolysis of the bond between the polypeptide chain and the tRNA
by binding a signal sequence, causing hydrolysis of the bond between the polypeptide chain and the tRNA
by “gumming up” the working of the ribosome, thus leading to the ribosome'ssecretion of protein release factors
Following is a list of five steps that occur during the initiation & elongation phases of translation. Which of the following would be considered the third step in this process?
Large ribosomal subunit binds to mRNA
Anticodon of initiator methionine-tRNA base pairs with its anticodon on mRNA
Small ribosomal subunit binds mRNA
Anticodon of charged tRNA base pairs with the codon at the A site
Peptide linkage forms
Which of the following occurs in the A site of the ribosome during translation
The tRNA carrying the growing protein moves to this site as the ribosome slides to the nextcodon
An uncharged tRNA is ejected from this site as the ribosome slides to the next codon.
An incoming charged tRNA (one that carries an amino acid) binds to this site.
What anticodon in Met-tRNA would pair with the codon 5'-AUG-3' in mRNA?
5'-GUA-3'
5'-UAC-3'
5'-ATG-3'
5'-AUG-3'
5'-CAU-3'
If a template DNA strand has the base sequence 3'-TACGTCTATGCATTAATT-5', what would be the sequence of the resulting transcribed RNA?
5'-TACGTCTATGCATTAATT-3'
5'-UACGUCUAUGCAUUAAUU-3'
5'-AUGCAGAUACGUAAUUAA-3'
5'-AAUUAAUGCAUAGACGUA-3'
3'-UACGUCUAUGCAUUAAUU-5'
What is the amino acid sequence of the peptide coded for by the mRNA in the previous question?
Methionine (Met)-Glutamine (Gln)-Isoleucine (Ile)-Arginine (Arg)-Asparagine (Asn)-Stop
Tyrosine (Tyr)-Valine (Val)-Tyrosine (Tyr)-Alanine (Ala)-Leucine (Leu)-Isoleucine (Ile)
Asparagine (Asn)-Stop
Leucine (Leu)-Isoleucine (Ile)-Threonine (Thr)-Tyrosine (Tyr)-Leucine (Leu)-Histidine(His)
Methionine (Met)-Histidine (His)-Stop
A mature mRNA molecule has the following sequence:
5'-AUGCGUCAUUCUCAAUGA-3'
A genetic mutation back in the DNA results in a different mRNA sequence in which the adenine at position 15 is replaced with guanine. What is the resulting effect on the protein translated from this mutated mRNA?
There is no effect; the original mRNA codon at this position was 5’-CAA-3’ while the mutated mRNA codon is 5’-CAG-3’. Both mRNA codons code for the same amino acid (glutamine)
The protein translated from this mutated mRNA will be shorter because the mutation will cause them RNA codon 5’-CAA-3’, which codes for an amino acid, to be changed to 5’-CAG-3’, which is a stop codon
The protein translated from this mutated mRNA will have a different amino acid at the position coded by this changed codon. The original mRNA at this position was 5’-AUG-3’ which codes for methionine, while the mutated mRNA codon is 5’-GUG-3’ which codes for valine
What enzyme catalyzes the attachment of an amino acid to tRNA?
kinase
poly A polymerase
helicase
RNA polymerase
aminoacyl-tRNA synthetase
A polysome is
the structure formed when a polypeptide is glycosylated
a signal sequence
the structure formed when multiple peptide chains are gathered together
a protein release factor
the structure formed when multiple ribosomes are translating an mRNA molecule
Epigenetics is the changing of the expression of a gene (or genes) by changing the _______ of DNA. It may be brought about by the _______ of cytosine or by the _______ of histones. These effects are _______.
structure; methylation; acetylation; reversible
sequence; acetylation; methylation; reversible
sequence; methylation; acetylation; reversible
structure; methylation; acetylation; irreversible
sequence; acetylation; acetylation; irreversible
Chromatin remodeling is a form of epigenetic regulation that can be accomplished by adding acetyl groups to histone proteins. When acetyl groups are added to histones by the enzyme______, the DNA associated with the histones becomes more ______ wrapped, and the level of transcription ______.
histone acetyltransferase; loosely; decreases
DNA demethylase; loosely; increases
histone deacetylase; tightly; decreases
histone acetyltransferase; loosely; increases
DNA methyltransferase; loosely; decreases
Heavy methylation of cytosines near the promoter of a gene is usually associated with repression of transcription
False
True
Put the following four steps of eukaryotic gene expression in order, from beginning to end.
(1) Pre-mRNA is processed to make mRNA.
(2) Ribosomes translate the mRNA message to make proteins.
(3) mRNA is transported to the cytoplasm.
(4) DNA is used as a template make pre-mRNA
4; 3; 1; 2
4; 1; 2; 3
1; 4; 3; 2
1; 2; 4; 3
4; 1; 3; 2
In many cases, more than one codon codes for the same amino acid. Because of this, we say that the code is __________.
inaccurate
incomplete
degenerate
not specific
