MICR 3033 Exam 2 Questions with
Revised Answers Graded A+
7Q1-How does DNA interact with the core histone nucleosome? - Answer-DNA wraps
around the core histone
7Q2-What is the length(fixed)of DNA(in base pairs) that wraps around a core
nucleosome? - Answer-147 base pairs
7Q3-What is the 30-nm fiber structure in chromatin? - Answer-solenoid
7Q4-What is meant by the terms Chromatin? Euchromatin? and Heterochromatin? -
Answer-Heterochromatin is condensed chromatin which makes it inactive. Euchromatin
is relaxed chromatin which makes it an active chromatin
7Q5-How is DNA configured into chromatin, compacted to heterochromatin and
reversed to chromatin? - Answer-DNA wrap around the histones then are clamped by
H1
7Q6-Describe the double helix nature of DNA. Why is it that DNA is always found as a
double stranded, antiparallel and complementary molecule? - Answer-complementary,
antiparallel, DNA replication
7Q7-What are histones and the structural components(DNA/proteins)of a nucleosome?
- Answer-proteins in chromatin that DNA wrap around, 4 proteins found in histone (2,
2B, 3, 4)
7Q8-Ponder on how you would describe the structure of histones and DNA in a
nucleosome? Please consider all relevant structural information contained in histones
that relate to DNA packaging. - Answer-proteins form histone, histones form histone
core, DNA wraps around histone core to form nucleosome
7Q9-What are the five classes of histones found in nucleosomes?Why are only four
histones found in the core histone nucleosome? - Answer-H1, H2A, H2B, H3, H4
H1 clamps and is not part of the core histone
7Q10-What is the role of histone H1? - Answer-H1 clamps the DNA to the histone core
7Q11-Which histones are found in the core nucleosome, and how do they interact? -
Answer-H2, H2B, H3, H4
H2 interacts with H2B and
, H3 interacts with H4 to form dimers and then tetramer the tetramers then form a core
histone
7Q12-A nucleoid in prokaryotes is different from a nucleus in eukaryotes because? -
Answer-
7Q13-How are genes organized on a DNA molecule? Consider prokaryotes and
eukaryotes for gene organization strategies at the DNA level. - Answer-coding region
and regulatory
7Q14-Besides of ORFs (which encode the amino acid sequence of a given protein)
what other features are encoded and stored in DNA? - Answer-Micro RNAs,
transposons, centromeres, telomeres, ORI
7Q15-Why is it possible that genes are transcribed from both DNA strands
(parallel/antiparallel)? - Answer-RNA polymerase can transcribed both strands in both
directions continuous and semi continuous
7Q16-Why is telomerase a ribozyme? Explain? - Answer-Adding a little piece of DNA,
nonsense sequence that repeats itself many times
7Q17-in trying to define a centromere, what DNA and protein components you think we
should play attention to? - Answer-
7Q18-Why are origins of replication (ORI) populated by that many protein complexes? -
Answer-They depend on sequence and number of proteins that bind to that region
7Q19-How can microRNAs interfere with gene expression (mRNA abundance)of a
target gene? - Answer-mRNA will no longer be able to make a protein which will not
create the protein or expres the gene
8.1Q1-What is the Central Dogma of Molecular Biology? Speaking of Informational
Pathways which paths are "2-way streets" and which ones are not? - Answer-DNA to
DNA (2 way) DNA to RNA (2 way) RNA to protein (1 way)
8.1Q2-What are the key structural differences between RNA and DNA? - Answer-Uracil
nucleic acid instead of Thymine
8.1Q3-What is meant by the DNA double-helix being "anti-parallel"? - Answer-Run in
opposite directions
8.1Q4-Why is the double-helical structure of DNA an excellent mechanical solution in
DNA replication? - Answer-DNA polymerase replicates both strands in both directions
Revised Answers Graded A+
7Q1-How does DNA interact with the core histone nucleosome? - Answer-DNA wraps
around the core histone
7Q2-What is the length(fixed)of DNA(in base pairs) that wraps around a core
nucleosome? - Answer-147 base pairs
7Q3-What is the 30-nm fiber structure in chromatin? - Answer-solenoid
7Q4-What is meant by the terms Chromatin? Euchromatin? and Heterochromatin? -
Answer-Heterochromatin is condensed chromatin which makes it inactive. Euchromatin
is relaxed chromatin which makes it an active chromatin
7Q5-How is DNA configured into chromatin, compacted to heterochromatin and
reversed to chromatin? - Answer-DNA wrap around the histones then are clamped by
H1
7Q6-Describe the double helix nature of DNA. Why is it that DNA is always found as a
double stranded, antiparallel and complementary molecule? - Answer-complementary,
antiparallel, DNA replication
7Q7-What are histones and the structural components(DNA/proteins)of a nucleosome?
- Answer-proteins in chromatin that DNA wrap around, 4 proteins found in histone (2,
2B, 3, 4)
7Q8-Ponder on how you would describe the structure of histones and DNA in a
nucleosome? Please consider all relevant structural information contained in histones
that relate to DNA packaging. - Answer-proteins form histone, histones form histone
core, DNA wraps around histone core to form nucleosome
7Q9-What are the five classes of histones found in nucleosomes?Why are only four
histones found in the core histone nucleosome? - Answer-H1, H2A, H2B, H3, H4
H1 clamps and is not part of the core histone
7Q10-What is the role of histone H1? - Answer-H1 clamps the DNA to the histone core
7Q11-Which histones are found in the core nucleosome, and how do they interact? -
Answer-H2, H2B, H3, H4
H2 interacts with H2B and
, H3 interacts with H4 to form dimers and then tetramer the tetramers then form a core
histone
7Q12-A nucleoid in prokaryotes is different from a nucleus in eukaryotes because? -
Answer-
7Q13-How are genes organized on a DNA molecule? Consider prokaryotes and
eukaryotes for gene organization strategies at the DNA level. - Answer-coding region
and regulatory
7Q14-Besides of ORFs (which encode the amino acid sequence of a given protein)
what other features are encoded and stored in DNA? - Answer-Micro RNAs,
transposons, centromeres, telomeres, ORI
7Q15-Why is it possible that genes are transcribed from both DNA strands
(parallel/antiparallel)? - Answer-RNA polymerase can transcribed both strands in both
directions continuous and semi continuous
7Q16-Why is telomerase a ribozyme? Explain? - Answer-Adding a little piece of DNA,
nonsense sequence that repeats itself many times
7Q17-in trying to define a centromere, what DNA and protein components you think we
should play attention to? - Answer-
7Q18-Why are origins of replication (ORI) populated by that many protein complexes? -
Answer-They depend on sequence and number of proteins that bind to that region
7Q19-How can microRNAs interfere with gene expression (mRNA abundance)of a
target gene? - Answer-mRNA will no longer be able to make a protein which will not
create the protein or expres the gene
8.1Q1-What is the Central Dogma of Molecular Biology? Speaking of Informational
Pathways which paths are "2-way streets" and which ones are not? - Answer-DNA to
DNA (2 way) DNA to RNA (2 way) RNA to protein (1 way)
8.1Q2-What are the key structural differences between RNA and DNA? - Answer-Uracil
nucleic acid instead of Thymine
8.1Q3-What is meant by the DNA double-helix being "anti-parallel"? - Answer-Run in
opposite directions
8.1Q4-Why is the double-helical structure of DNA an excellent mechanical solution in
DNA replication? - Answer-DNA polymerase replicates both strands in both directions
