BS 161 EXAM 3 Detailed Study
Questions with Verified Answers
Already Graded A+
1. thymine - ANSWER pyrimidine
2. guanine - ANSWER purine
3. cytosine - ANSWER pyrimidine
4. x-ray diffraction - ANSWER Rosalind Franklin used this technique to
expose the double helix structure of DNA
5. Keto vs. Enol forms of nucleotides - ANSWER in DNA. Chemical
equilibrium between a keto form (a ketone or an aldehyde) and an enol (an
alcohol)
6. phosphodiester bonds - ANSWER phosphate group is now linked to the two
sugars by means of a pair of ester bonds. Makes up backbone of DNA
7. conservative replication - ANSWER strands of the parental duplex would
remain intact (conserved), and both strands of the new DNA duplex would
contain all-new nucleotides
8. semiconservative replication - ANSWER ***DNA
,one strand of the parental duplex remains intact in daughter strands (semi
conserved), with a new complementary strand built for each parental strand
consisting of new nucleotides
9. signal transduction pathway - ANSWER interaction of membrane receptor
and intracellular receptor.
converts the information in the external signal into a cellular response
10.chemically gated ion channel - ANSWER channel-linked receptors that
open to let a specific ion pass in response to a ligand
type of membrane receptor
11.A part of the promoter, called the TATA box, is said to be highly conserved
in evolution. Which of the following might this illustrate?
The sequence is transcribed at the start of every gene.
The sequence is found in many but not all promoters.
Any mutation in the sequence is selected against.
The sequence does not mutate.
The sequence evolves very rapidly. - ANSWER Any mutation in the sequence
is selected against.
12.For any given gene, what ultimately determines which DNA strand serves as
the template strand?
which of the two strands of DNA carries the RNA primer
the location of specific proteins (transcription factors) that bind to the DNA
the location along the chromosome where the double-stranded DNA unwinds
the base sequence of the gene's promoter - ANSWER the base sequence of the
gene's promoter
, 13.During splicing, which molecular component of the spliceosome catalyzes
the excision reaction?
protein
DNA
sugar
RNA
lipid - ANSWER RNA
14.RNA polymerase moves in which direction along the DNA?
3' to 5' along the nontemplate strand
5' to 3' along whichever strand it's on
5' to 3' along the template strand
5' to 3' along the double-stranded DNA
3' to 5' along the template strand - ANSWER 3' to 5' along the template strand
15.When the spliceosome binds to this transcript, where can it attach?
to the 3' UTR
to the 5' UTR
to an adjacent intron and exon
to the exons
at certain sites along an intron - ANSWER at certain sites along an intron
16.Which of the following experimental procedures is most likely to hasten
mRNA degradation in a eukaryotic cell?
methylation of histones
Questions with Verified Answers
Already Graded A+
1. thymine - ANSWER pyrimidine
2. guanine - ANSWER purine
3. cytosine - ANSWER pyrimidine
4. x-ray diffraction - ANSWER Rosalind Franklin used this technique to
expose the double helix structure of DNA
5. Keto vs. Enol forms of nucleotides - ANSWER in DNA. Chemical
equilibrium between a keto form (a ketone or an aldehyde) and an enol (an
alcohol)
6. phosphodiester bonds - ANSWER phosphate group is now linked to the two
sugars by means of a pair of ester bonds. Makes up backbone of DNA
7. conservative replication - ANSWER strands of the parental duplex would
remain intact (conserved), and both strands of the new DNA duplex would
contain all-new nucleotides
8. semiconservative replication - ANSWER ***DNA
,one strand of the parental duplex remains intact in daughter strands (semi
conserved), with a new complementary strand built for each parental strand
consisting of new nucleotides
9. signal transduction pathway - ANSWER interaction of membrane receptor
and intracellular receptor.
converts the information in the external signal into a cellular response
10.chemically gated ion channel - ANSWER channel-linked receptors that
open to let a specific ion pass in response to a ligand
type of membrane receptor
11.A part of the promoter, called the TATA box, is said to be highly conserved
in evolution. Which of the following might this illustrate?
The sequence is transcribed at the start of every gene.
The sequence is found in many but not all promoters.
Any mutation in the sequence is selected against.
The sequence does not mutate.
The sequence evolves very rapidly. - ANSWER Any mutation in the sequence
is selected against.
12.For any given gene, what ultimately determines which DNA strand serves as
the template strand?
which of the two strands of DNA carries the RNA primer
the location of specific proteins (transcription factors) that bind to the DNA
the location along the chromosome where the double-stranded DNA unwinds
the base sequence of the gene's promoter - ANSWER the base sequence of the
gene's promoter
, 13.During splicing, which molecular component of the spliceosome catalyzes
the excision reaction?
protein
DNA
sugar
RNA
lipid - ANSWER RNA
14.RNA polymerase moves in which direction along the DNA?
3' to 5' along the nontemplate strand
5' to 3' along whichever strand it's on
5' to 3' along the template strand
5' to 3' along the double-stranded DNA
3' to 5' along the template strand - ANSWER 3' to 5' along the template strand
15.When the spliceosome binds to this transcript, where can it attach?
to the 3' UTR
to the 5' UTR
to an adjacent intron and exon
to the exons
at certain sites along an intron - ANSWER at certain sites along an intron
16.Which of the following experimental procedures is most likely to hasten
mRNA degradation in a eukaryotic cell?
methylation of histones
