Problem 7.10a
Which of the following methods of DNA repair involves enzymes that recognize and correct nucleotide errors in unmethylated strands of DNA?
a. light repair of T dimers
b. dark repair of P dimers
c. mismatch repair
d. SOS response
Problem 7.1a
On the accompanying figure, label DNA polymerase I, DNA polymerase III, helicase, lagging strand, leading strand, ligase, nucleotide (triphosphate), Okazaki fragment, primase, replication fork, RNA primer, and stabilizing proteins.
<IMAGE>
Problem 7.1a
How does the genotype of a bacterium determine its phenotype? Use the terms gene, mRNA, ribosome, and polypeptide in your answer.
Problem 7.1a
The three steps in RNA transcription are __________ , ___________ , and __________ .
Problem 7.10a
Explain the central dogma of genetics.
Problem 7.10a
____________________ is a recombination event that occurs during gamete formation in eukaryotes.
Problem 7.11a
__________ RNA carries amino acids.
Problem 7.11a
Compare and contrast the processes of transformation, transduction, and conjugation.
Problem 7.11a
Which of the following is not a mechanism of genetic transfer between cells?
a. transduction
b. transformation
c. transcription
d. conjugation
Problem 7.12a
__________ RNA and __________ RNA are antisense; that is, they are complementary to another nucleic acid molecule.
Problem 7.12a
Fill in the following table:
<IMAGE>
Problem 7.12a
Cells that have the ability to take up DNA from their environment are said to be ___________.
a. Hfr cells
b. transposing
c. genomic
d. competent
Problem 7.13a
Which of the following statements is true?
a. Conjugation requires a sex pilus extending from the surface of a cell.
b. Conjugation involves a C factor.
c. Conjugation is an artificial genetic engineering technique.
d. Conjugation involves DNA that has been released into the environment.
Problem 7.14a
Which of the following are called “jumping genes”?
a. Hfr cells
b. transducing phages
c. palindromic sequences
d. transposons
Problem 7.15a
Although two cells are totally unrelated, one cell receives DNA from the other cell and incorporates this new DNA into its chromosome. This process is ___________.
a. crossing over of DNA from the two cells
b. vertical gene transfer
c. horizontal gene transfer
d. transposition
Problem 7.16a
Transcription produces _____________ .
a. DNA molecules
b. RNA molecules
c. polypeptides
d. palindromes
Problem 7.19a
A sequence of nucleotides formed during replication of the lagging DNA strand is a(n) ___________ .
a. palindrome
b. Okazaki fragment
c. coding strand
d. operon
Problem 7.2a
Which of the following is a true statement concerning prokaryotic chromosomes?
a. They typically have two or three origins of replication.
b. They contain single-stranded DNA.
c. They are located in the cytosol.
d. They are associated in linear pairs.
Problem 7.2a
This bacteriophage DNA molecule has been warmed. Label the portions that likely have a higher ratio of GC base pairs and the portions that have a higher ratio of AT base pairs.
<IMAGE>
Problem 7.20a
Which of the following is not part of an operon?
a. operator
b. promoter
c. origin
d. gene
Problem 7.2a
List several ways in which eukaryotic messenger RNA differs from prokaryotic mRNA.
Problem 7.2a
A triplet of mRNA nucleotides that specifies a particular amino acid is called a ____________ .
Problem 7.21a
Repressible operons are important in regulating prokaryotic .
a. DNA replication
b. RNA transcription
c. rRNA processing
d. sugar catabolism
Problem 7.22a
Which of the following is part of each molecule of mRNA?
a. palindrome
b. codon
c. anticodon
d. base pair
Problem 7.23a
Ligase plays a major role in ____________ .
a. replication of lagging strands
b. mRNA processing in eukaryotes
c. polypeptide synthesis by ribosomes
d. RNA transcription
Problem 7.24a
Before mutations can affect a population permanently, they must be __________ .
a. lasting
b. inheritable
c. beneficial
d. all of the above
Problem 7.25a
The trp operon is repressible. This means it is usually __________ and is directly controlled by a(n) ___________ .
a. active / inducer
b. active / repressor
c. inactive / inducer
d. inactive /repressor
Problem 7.3a
The drugs ddC and AZT are used to treat AIDS.
<IMAGE> <IMAGE>
ddC (2', 3'- dideoxycytidine AZT (3'-azido-2', 3'- dideoxythymidine)
Based on their chemical structures, what is their mode of action?
Problem 7.3a
Three effects of point mutations are ___________ , ___________ , and ____________ .
Problem 7.4a
Which of the following forms ionic bonds with eukaryotic DNA and stabilizes it?
a. chromatin
b. bacteriocin
c. histone
d. nucleoid
Ch. 7 - Microbial Genetics