Bio 203 Exam 4 practice test questions &
answers (100% Correct)
What is the reason that closely linked genes are typically inherited together?
The likelihood of a crossover event between these two genes is low
All female mammals have one active X chromosome per cell instead of two. What
causes this?
Activation of the XIST gene on the X chromosome that will become the Barr body
In his transformation experiments, what did Griffith observe?
Mixing a heat-killing pathogenic strain of bacteria with a living nonpathogenic strain can
convert some of the living cells into the pathogenic form
In trying to determine whether DNA or protein is the genetic material of phage
using radioisotopes, Hershey and Chase made use if which of the following
facts?
DNA contains phosphorus, whereas protein does not
Why is the new DNA strand complementary to the 3' to 5' strands assembled in
short segments?
DNA polymerase can assemble DNA only in the 5' to 3' direction
Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism.
Approximately what percentage of the nucleotides in this sample will be thymine?
8%
DNA replication is said to be semiconservative. What does that mean?
Each new double helix consists of one old and one new strand
What are the repetitive DNA sequences present at the ends of eukaryotic
chromosomes called?
Telomeres
DNA replication image:
Enzyme that untwists the double helix at the replication forks
C
DNA replication image:
Enzyme that corrects "overwinding" ahead of replication forks
A
DNA replication image:
Enzyme that adds RNA nucleotides using the parental DNA as a template
B
DNA replication image:
proteins that bind to and stabilize single-stranded DNA
D
A particular triplet of bases in the template strand of DNA is 5' CTA 3'. The
corresponding codon for the mRNA transcribed is
3' GAU 5'
At a specific area of a chromosome, the sequence of nucleotides below is present
where the chain opens to form a replication fork: 3' CCTAGGC T CGAATGG 5'. An
, RNA primer is formed starting at the underlined T (T) of the template. Which of
the following represents the primer sequence?
5' AGCUUACC 3'
Neurospora crassa growth data:
Require arginine to grow
Class III
Neurospora crassa growth data:
Can grow only on citruline or arginine
Class II
Neurospora crassa growth data:
Can grow with or without any supplements
Wild type
Neurospora crassa growth data:
Can grow on orinithine, citrulline, or arginine
Class I
Accuracy in the translation of mRNA into the primary structure of a polypeptide
depends on specificity in the
Bonding of the anticodon to the codon and the attachment of amino acids to tRNAs
A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a
lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The
consequences of this for the cell will be that
Proteins in the cell will include lysine instead of phenylalanine at the amino acid
positions specified by the codon UUU
When translating secretory or membrane proteins, ribosomes are directed to the
ER membrane by
a signal-recognition particle that brings ribosomes to a receptor protein in the ER
membrane
Which of the following DNA mutations is the least likely to be damaging to the
protein it specifies?
A substitution in the last base of a codon
The figure below demonstrates the outcome of the following type of mutation:
(1 nucleotide pair deletion)
Frameshift causing extensive missense
Which of the following does not occur in prokaryotic gene expression, but does
occur in eukaryotic gene expression?
A ply-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end
The average length of a transcription unit along with a eukaryotic DNA molecule
is about 27kb nucleotide pairs, whereas an averaged-size protein id about 400
amino acids long. What is the best explanation for this fact?
Most eukaryotic genes and their RNA transcripts have long noncoding stretches of
nucleotides that are not translated
The tryptophan operon is a repressible operon that is
Turned off whenever tryptophan is added to the growth medium
If you were to observe the activity of methylated DNA, you would expect it to
Have turned off or slowed down the process of transcription
In eukaryotes, general transcription factors
answers (100% Correct)
What is the reason that closely linked genes are typically inherited together?
The likelihood of a crossover event between these two genes is low
All female mammals have one active X chromosome per cell instead of two. What
causes this?
Activation of the XIST gene on the X chromosome that will become the Barr body
In his transformation experiments, what did Griffith observe?
Mixing a heat-killing pathogenic strain of bacteria with a living nonpathogenic strain can
convert some of the living cells into the pathogenic form
In trying to determine whether DNA or protein is the genetic material of phage
using radioisotopes, Hershey and Chase made use if which of the following
facts?
DNA contains phosphorus, whereas protein does not
Why is the new DNA strand complementary to the 3' to 5' strands assembled in
short segments?
DNA polymerase can assemble DNA only in the 5' to 3' direction
Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism.
Approximately what percentage of the nucleotides in this sample will be thymine?
8%
DNA replication is said to be semiconservative. What does that mean?
Each new double helix consists of one old and one new strand
What are the repetitive DNA sequences present at the ends of eukaryotic
chromosomes called?
Telomeres
DNA replication image:
Enzyme that untwists the double helix at the replication forks
C
DNA replication image:
Enzyme that corrects "overwinding" ahead of replication forks
A
DNA replication image:
Enzyme that adds RNA nucleotides using the parental DNA as a template
B
DNA replication image:
proteins that bind to and stabilize single-stranded DNA
D
A particular triplet of bases in the template strand of DNA is 5' CTA 3'. The
corresponding codon for the mRNA transcribed is
3' GAU 5'
At a specific area of a chromosome, the sequence of nucleotides below is present
where the chain opens to form a replication fork: 3' CCTAGGC T CGAATGG 5'. An
, RNA primer is formed starting at the underlined T (T) of the template. Which of
the following represents the primer sequence?
5' AGCUUACC 3'
Neurospora crassa growth data:
Require arginine to grow
Class III
Neurospora crassa growth data:
Can grow only on citruline or arginine
Class II
Neurospora crassa growth data:
Can grow with or without any supplements
Wild type
Neurospora crassa growth data:
Can grow on orinithine, citrulline, or arginine
Class I
Accuracy in the translation of mRNA into the primary structure of a polypeptide
depends on specificity in the
Bonding of the anticodon to the codon and the attachment of amino acids to tRNAs
A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a
lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The
consequences of this for the cell will be that
Proteins in the cell will include lysine instead of phenylalanine at the amino acid
positions specified by the codon UUU
When translating secretory or membrane proteins, ribosomes are directed to the
ER membrane by
a signal-recognition particle that brings ribosomes to a receptor protein in the ER
membrane
Which of the following DNA mutations is the least likely to be damaging to the
protein it specifies?
A substitution in the last base of a codon
The figure below demonstrates the outcome of the following type of mutation:
(1 nucleotide pair deletion)
Frameshift causing extensive missense
Which of the following does not occur in prokaryotic gene expression, but does
occur in eukaryotic gene expression?
A ply-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end
The average length of a transcription unit along with a eukaryotic DNA molecule
is about 27kb nucleotide pairs, whereas an averaged-size protein id about 400
amino acids long. What is the best explanation for this fact?
Most eukaryotic genes and their RNA transcripts have long noncoding stretches of
nucleotides that are not translated
The tryptophan operon is a repressible operon that is
Turned off whenever tryptophan is added to the growth medium
If you were to observe the activity of methylated DNA, you would expect it to
Have turned off or slowed down the process of transcription
In eukaryotes, general transcription factors
