ANSWERS |LATEST UPDATE!!!
What type of bonds are formed between complementary DNA bases? - ANS ...
Hydrogen Bonds
Which of the following forms the backbone of a polynucleotide chain? - ANS ...
alternating sugar and phosphate groups
Guanine and adenine are purines found in DNA - ANS ... true
What fraction of the nucleotides in a doubles-stranded DNA molecule are cytosine
and thymine? - ANS ... 50%
What is one difference between DNA replication in bacteria versus eukaryotes? -
ANS ... Eukaryotic chromosomes have many origins of replication, while bacteria
have only one origin of replication
What is the maximum rate between DNA replication in E. coli - ANS ... 1000
nucleotides?
During DNA replication in E. coli, what is the role of DnaA? - ANS ... DnaA bends
DNA, hydrolyzing the hydrogen bonds in the 13-mer region of otic and creating an
open complex
Which of the following statements about DNA replication is true? - ANS ... Single-
strand binding proteins stabilize the open conformation of the unwound DNA
,Which of the following reagents is not required for the polymerase chain reaction? -
ANS ... Dideoxynucleotide triphosphate
Which of the following would you find in a Sanger sequencing reaction but not in a
polymerase chain reaction? - ANS ... ddNTPs
Which of the following statements about ddNTPs is true? - ANS ... they have a
hydrogen at the 3' carbon of the sugar
The principles of complementary base pairing and antiparallel polarity of nucleic
acid strands is a duplex are universal for the formation of nucleic acid duplexes.
What is the chemical basis for this university? - ANS ...
You wish to create a mutation in which you prevent access of RNA polymerase to
the gene. Which region of a gene would you target? - ANS ... promoter sequence
Which region(s) of a gene are not found within the mRNA transcript? - ANS ...
promoter region
Which of the following statements regarding Nucleotide Excision repair (NER) and
Base Excision Repair (BER) is true? - ANS ... both NER and BER involve the removal
of one or more damaged bases by a nuclease
How large is an origin of replication of E. coli? - ANS ... 245 base pairs
Which of the following enzymatic activities is NOT involved in DNA replication -
ANS ... RNA- dependent DNA polymerase
,Which activity of DNA polymerase is responsible for its ability to proofread newly
synthesized DNA - ANS ... 3'>5' exonuclease which cleaves mismatched nucleotides
How many mutations would you expect to see in the human genome (6x10^9) if
mismatches could not be repaired? - ANS ... 6x10^9/10^4= 600,000 mutations
What would the consequences be of having DNA polymerase with out 5' -> 3'
exonuclease activity? - ANS ... the RNA primer will stay
What is the correct order of enzyme action during DNA replication? - ANS ...
helices/topoisomerase activity, priming, DNA polymerization/proofreading, 5'-3'
exonuclease activity/DNA polymerization, ligation
Why is telomerase important? - ANS ... It is important for extension
You isolate a mutant of this gene that encodes the following protein:
N-Met-Gln-Cys-Lys-Ser-C
What mutation can give you this mutant protein - ANS ... Deletion of a C
Which of the following statements are FALSE? - ANS ... the Trp Operon is under
positive control
*LAC has both positive and negative regulation* - ANS ...
Trp is negative controlled - ANS ...
Under which of the following conditions will E. coli make large amounts of B-
galactosidase? - ANS ... I+O+Z+, glucose absent, lactose present
I-OcZ+, glucose absent, lactose absent
, Under what condition will E. coli make the least amount of B-galactosidase? - ANS
... IsO+Z+, glucose absent, lactose present
For the lac operon gene regulation system, which of the following is false? - ANS ...
in the presence of low levels of glucose and lactose, even with mutation happening
on the operator (operator cannot bind to repressor), there are still no transcription
of lac genes
The expression of a gene can be increase by? - ANS ... knocking out its repressor
In the Trp operon of E. coli, the Trytophan repressor protein, Trp R, will bind to the
operator to prevent transcription only in the presence of tryptophan. What is
tryptophan an example of? - ANS ... Co-repressor
Which of the following is required for transcription - ANS ... RNA polymerase
Which of the following nucleosomes modifications will lead to closed promoters -
ANS ... De-acetylation
All of the following codons/anticodons are associated with the amino acid Leucine.
Which of the following anti-codon/codon pairs is an example of wobble paring -
ANS ... Anticodon: 5' UAA 3' paired with codon
5' UUA 3' or 5' UUG 3'
Why are mitochondria and plastid genomes highly reduced compared to their free
living relatives (Ammar) - ANS ... Gene loss and Endosymbiotic Gene Transfer
Where are most Mitochondrial genes encoded? - ANS ... Nucleus