MAMMALIAN GENETICS BCH5413 EXAM 1
WITH QUESTIONS AND CORRECT
ANSWERS
Because the DNA was not destroyed, meaning that the pathogenic
strain is still able to be taken up by the healthy DNA, causing death -
ANSWER Why does the mouse die if the researcher mixes the dead
pathogenic strain with the live non-pathogenic strain bacteria and
then inject it into the mouse?
When the DNA was completely destroyed; the S strain was no longer
able to be pathogenic without its DNA - ANSWER What was the only
scenario in which the mouse lives? Why?
3.4 A - ANSWER How many angstroms is the distance between
stacked base pairs in DNA?
1953 - ANSWER What year was the structure of DNA discovered?
They did x-ray crystallography to discover the "X" helix pattern of
DNA - ANSWER How did Wilkins and Franklin contribute to the
discovery of DNA's structure?
A phosphate, a 5-C sugar, and a nitrogenous base - ANSWER What
are the 3 components of a nucleotide?
They made a model of the structure of helical DNA using others'
previous research - ANSWER How did Watson and Crick contribute
to the discovery of DNA's structure?
A nitrogenous base (A, G, T, or C) - ANSWER What is attached to the
1' C in DNA's 5-C sugar?
A and G - ANSWER Which bases are the purines?
C, T, and U - ANSWER Which bases are the pyrimidines?
,True - ANSWER T/F: Purines have a double-ring structure while
pyrimidines have a single-ring structure.
An -H group (if DNA) or an -OH group (if RNA) - ANSWER What is
attached to the 2' C in DNA's 5-C sugar?
An -OH group (will interact with the phosphate on the 5' C of the next
nucleotide) - ANSWER What is attached to the 3' C in DNA's 5-C
sugar?
It completes the ring structure (connects the 5' C and 3' C to the
oxygen in the ring) - ANSWER What is attached to the 4' C in DNA's
5-C sugar?
A phosphate group (will interact with the -OH group on the 3' C of the
next nucleotide) - ANSWER What is attached to the 5' C in DNA's 5-C
sugar?
The phosphate group losing an oxygen in water - ANSWER What
gives DNA its (-) charge?
It connects from phosphate group -> -OH group -> phosphate group,
etc. (never backwards), which allows the nitrogenous bases to
hydrogen bond - ANSWER Why does DNA have directionality?
One single-strand of DNA is 5' -> 3' and the other strand it connects
to is 3' -> 5' (the strands do not connect in the same direction to form
dsDNA) - ANSWER What does it mean that DNA is antiparallel?
That DNA replication is semiconservative (the parent strand unzips
to allow for synthesis of a new strand) - ANSWER What does the
Meselson and Stahl experiment (1958) confirm?
True (the presence of 4 bps instead of 3 bps like in the minor groove
allows for a more unique pattern of binding) - ANSWER T/F: The
major groove in DNA's structure allows for more specificity in binding
proteins.
False (linear DNA can be supercoiled if in a cell because of its
association with proteins) - ANSWER T/F: Eukaryotic DNA in the
,nucleus of cells will not supercoil since it's liner.
False (it needs the presence of other cellular components to
supercoil) - ANSWER T/F: Linear DNA in a test tube (no other
substances present) is able to be supercoiled.
Positive supercoil - ANSWER The type of supercoil in which DNA is
twisted more tightly in the right-hand direction
Negative supercoil - ANSWER The type of supercoil in which DNA is
twisted more loosely in the left-hand direction
Negative supercoil - ANSWER Which type of supercoil allows the
DNA to be more accessible for replication and transcription?
False (GC-rich DNA has more hydrogen bonds and is more stable,
giving it a higher melting temperature) - ANSWER T/F: GC-rich DNA
has a lower melting temperature than AT-rich DNA.
False (A = T and G = C; the amount of purines and pyrimidines in DNA
will always be equal; A+G = C+T) - ANSWER T/F: Chargaff's rule is
that A=G and T=C.
True (this cancels out the phosphate's negative charge allowing for a
more stable interaction of the DNA backbone) - ANSWER T/F:
Increased salt concentration increases the stability of complimentary
base pairing.
B-DNA - ANSWER What is the name of the most common ("normal")
form of DNA?
10 bp - ANSWER B-DNA has how many bps per helical turn?
A-DNA - ANSWER Is A-DNA or Z-DNA a right-handed helix?
Z-DNA - ANSWER Which type of DNA is favored by GC repeats and
alternating purines/pyrimidines?
Cruciform DNA - ANSWER Which type of DNA is favored by AT-rich
areas of fragile DNA?
, A-DNA (has a looser structure) - ANSWER Is A-DNA or Z-DNA the
dehydrated form?
Cruciform DNA - ANSWER Which type of DNA is caused by inverted
repeat sequences?
Z-DNA (A-DNA has 11 bp per helical turn) - ANSWER Does A-DNA or
Z-DNA have 12 bp per helical turn?
(1) DNA has thymine and RNA has uracil; (2) DNA has an -H on its 2' C
and RNA has an -OH group; (3) DNA is normally double-stranded
while RNA is normally single-stranded - ANSWER What are 3
differences between DNA and RNA?
(1) Both have A/G/C as nitrogenous bases; (2) both are composed of
nucleotides; (3) both are a form of genetic material; (4) both have 5'
-> 3' directionality; (5) both can form secondary/tertiary structures -
ANSWER What are 3 similarities between DNA and RNA?
The flow of genetic information from DNA -> mRNA -> proteins
through replication, transcription, and translation - ANSWER What is
the central dogma?
(1) tRNA doesn't need to be translated into proteins because its used
in the translation process; (2) rRNA makes up ribosomes and doesn't
need to be translated - ANSWER What are 2 examples of RNA that
are exceptions to the central dogma?
(1) Gene expression (encoding for specific proteins, can change
depending on the environment); (2) gene replication (allows the
passing on of genetic material through mitosis/meiosis) - ANSWER
What are the 2 functions of DNA in cells?
Diploid - ANSWER What does it mean to have 2 copies of
chromosomes?
Allele - ANSWER The 2 versions of the same gene found at the same
location on a homologous pair of chromosomes.
Heterozygous - ANSWER What does it mean to have 2 different
WITH QUESTIONS AND CORRECT
ANSWERS
Because the DNA was not destroyed, meaning that the pathogenic
strain is still able to be taken up by the healthy DNA, causing death -
ANSWER Why does the mouse die if the researcher mixes the dead
pathogenic strain with the live non-pathogenic strain bacteria and
then inject it into the mouse?
When the DNA was completely destroyed; the S strain was no longer
able to be pathogenic without its DNA - ANSWER What was the only
scenario in which the mouse lives? Why?
3.4 A - ANSWER How many angstroms is the distance between
stacked base pairs in DNA?
1953 - ANSWER What year was the structure of DNA discovered?
They did x-ray crystallography to discover the "X" helix pattern of
DNA - ANSWER How did Wilkins and Franklin contribute to the
discovery of DNA's structure?
A phosphate, a 5-C sugar, and a nitrogenous base - ANSWER What
are the 3 components of a nucleotide?
They made a model of the structure of helical DNA using others'
previous research - ANSWER How did Watson and Crick contribute
to the discovery of DNA's structure?
A nitrogenous base (A, G, T, or C) - ANSWER What is attached to the
1' C in DNA's 5-C sugar?
A and G - ANSWER Which bases are the purines?
C, T, and U - ANSWER Which bases are the pyrimidines?
,True - ANSWER T/F: Purines have a double-ring structure while
pyrimidines have a single-ring structure.
An -H group (if DNA) or an -OH group (if RNA) - ANSWER What is
attached to the 2' C in DNA's 5-C sugar?
An -OH group (will interact with the phosphate on the 5' C of the next
nucleotide) - ANSWER What is attached to the 3' C in DNA's 5-C
sugar?
It completes the ring structure (connects the 5' C and 3' C to the
oxygen in the ring) - ANSWER What is attached to the 4' C in DNA's
5-C sugar?
A phosphate group (will interact with the -OH group on the 3' C of the
next nucleotide) - ANSWER What is attached to the 5' C in DNA's 5-C
sugar?
The phosphate group losing an oxygen in water - ANSWER What
gives DNA its (-) charge?
It connects from phosphate group -> -OH group -> phosphate group,
etc. (never backwards), which allows the nitrogenous bases to
hydrogen bond - ANSWER Why does DNA have directionality?
One single-strand of DNA is 5' -> 3' and the other strand it connects
to is 3' -> 5' (the strands do not connect in the same direction to form
dsDNA) - ANSWER What does it mean that DNA is antiparallel?
That DNA replication is semiconservative (the parent strand unzips
to allow for synthesis of a new strand) - ANSWER What does the
Meselson and Stahl experiment (1958) confirm?
True (the presence of 4 bps instead of 3 bps like in the minor groove
allows for a more unique pattern of binding) - ANSWER T/F: The
major groove in DNA's structure allows for more specificity in binding
proteins.
False (linear DNA can be supercoiled if in a cell because of its
association with proteins) - ANSWER T/F: Eukaryotic DNA in the
,nucleus of cells will not supercoil since it's liner.
False (it needs the presence of other cellular components to
supercoil) - ANSWER T/F: Linear DNA in a test tube (no other
substances present) is able to be supercoiled.
Positive supercoil - ANSWER The type of supercoil in which DNA is
twisted more tightly in the right-hand direction
Negative supercoil - ANSWER The type of supercoil in which DNA is
twisted more loosely in the left-hand direction
Negative supercoil - ANSWER Which type of supercoil allows the
DNA to be more accessible for replication and transcription?
False (GC-rich DNA has more hydrogen bonds and is more stable,
giving it a higher melting temperature) - ANSWER T/F: GC-rich DNA
has a lower melting temperature than AT-rich DNA.
False (A = T and G = C; the amount of purines and pyrimidines in DNA
will always be equal; A+G = C+T) - ANSWER T/F: Chargaff's rule is
that A=G and T=C.
True (this cancels out the phosphate's negative charge allowing for a
more stable interaction of the DNA backbone) - ANSWER T/F:
Increased salt concentration increases the stability of complimentary
base pairing.
B-DNA - ANSWER What is the name of the most common ("normal")
form of DNA?
10 bp - ANSWER B-DNA has how many bps per helical turn?
A-DNA - ANSWER Is A-DNA or Z-DNA a right-handed helix?
Z-DNA - ANSWER Which type of DNA is favored by GC repeats and
alternating purines/pyrimidines?
Cruciform DNA - ANSWER Which type of DNA is favored by AT-rich
areas of fragile DNA?
, A-DNA (has a looser structure) - ANSWER Is A-DNA or Z-DNA the
dehydrated form?
Cruciform DNA - ANSWER Which type of DNA is caused by inverted
repeat sequences?
Z-DNA (A-DNA has 11 bp per helical turn) - ANSWER Does A-DNA or
Z-DNA have 12 bp per helical turn?
(1) DNA has thymine and RNA has uracil; (2) DNA has an -H on its 2' C
and RNA has an -OH group; (3) DNA is normally double-stranded
while RNA is normally single-stranded - ANSWER What are 3
differences between DNA and RNA?
(1) Both have A/G/C as nitrogenous bases; (2) both are composed of
nucleotides; (3) both are a form of genetic material; (4) both have 5'
-> 3' directionality; (5) both can form secondary/tertiary structures -
ANSWER What are 3 similarities between DNA and RNA?
The flow of genetic information from DNA -> mRNA -> proteins
through replication, transcription, and translation - ANSWER What is
the central dogma?
(1) tRNA doesn't need to be translated into proteins because its used
in the translation process; (2) rRNA makes up ribosomes and doesn't
need to be translated - ANSWER What are 2 examples of RNA that
are exceptions to the central dogma?
(1) Gene expression (encoding for specific proteins, can change
depending on the environment); (2) gene replication (allows the
passing on of genetic material through mitosis/meiosis) - ANSWER
What are the 2 functions of DNA in cells?
Diploid - ANSWER What does it mean to have 2 copies of
chromosomes?
Allele - ANSWER The 2 versions of the same gene found at the same
location on a homologous pair of chromosomes.
Heterozygous - ANSWER What does it mean to have 2 different
