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Problem 1
Which of the following is most likely the number of base pairs in a bacterial chromosome?
a. 4,000,000
b. 4000
c. 400
d. 40
Problem 2
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 3
A plasmid is __________ .
a. a molecule of RNA found in bacterial cells
b. distinguished from a chromosome by being circular
c. a structure in bacterial cells formed from plasma membrane
d. extrachromosomal DNA
Problem 4
Which of the following forms ionic bonds with eukaryotic DNA and stabilizes it?
a. Chromatin
b. Bacteriocin
c. Histone
d. Nucleoid
Problem 5
Nucleotides used in the replication of DNA __________ .
a. Carry energy
b. Are found in four forms, each with a deoxyribose sugar, a phosphate, and a base
c. Are present in cells as triphosphate nucleotides
d. All of the above are correct.
Problem 6
Which of the following molecules functions as a “proofreader” for a newly replicated strand of DNA?
a. DNA polymerase III
b. Primase
c. Helicase
d. Ligase
Problem 7
The addition of a ----CH3 to a cytosine nucleotide after DNA replication is called: .
a. Methylation
b. Restriction
c. Transcription
d. Transversion
Problem 8
In translation, the site through which tRNA molecules leave a ribosome is called the:
a. A site
b. X site
c. P site
d. E site
Problem 9
The Ames test ___________.
a. uses auxotrophs and liver extract to reveal mutagens
b. s time intensive and costly
c. involves the isolation of a mutant by eliminating wild-type phenotypes with specific media
d. proves that suspected chemicals are carcinogenic
Problem 10
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 11
Which of the following is not a mechanism of genetic transfer between cells?
a. Transduction
b. Transformation
c. Transcription
d. Conjugation
Problem 12
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 13
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 14
Which of the following are called “jumping genes”?
a. Hfr cells
b. Transducing phages
c. Palindromic sequences
d. Transposons
Problem 15
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 16
Transcription produces:
a. DNA molecules
b. RNA molecules
c. Polypeptides
d. Palindromes
Problem 17
A nucleotide is made of:
a. A five-carbon sugar
b. Phosphate
c. A nitrogenous base
d. All of the above
Problem 19
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 20
Which of the following is not part of an operon?
a. Operator
b. Promoter
c. Origin
d. Gene
Problem 21
Repressible operons are important in regulating prokaryotic:
a. DNA replication
b. RNA transcription
c. rRNA processing
d. Sugar catabolism
Problem 22
Which of the following is part of each molecule of mRNA?
a. Palindrome
b. Codon
c. Anticodon
d. Base pair
Problem 23
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 24
Before mutations can affect a population permanently, they must be __________ .
a. lasting
b. inheritable
c. beneficial
d. all of the above
Problem 25
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 1
The three steps in RNA transcription are __________ , ___________ , and __________ .
Problem 2
A triplet of mRNA nucleotides that specifies a particular amino acid is called a ____________ .
Problem 3
Three effects of point mutations are ___________ , ___________ , and ____________ .
Problem 4
Insertions and deletions in the genetic code are also called ___________ mutations.
Problem 5
An operon consists of __________ , ___________ , and __________ , and is associated with a regulatory gene.
Problem 6
In general, __________ operons are inactive until the substrate of their genes’ polypeptides is present.