The base sequence of a messenger RNA molecule that is complementary to the sequence CGTTAGA would be expressed as
Which one of the following does not apply to plasmids?
A. They are essential for growth
B. They are composed of DNA
C. They multiply independently of the chromosome
D. They exist as closed loops
The major activity of transcription is to
A. copy DNA.
B. pair codons with anticodons.
C. produce amino acids.
D. produce RNA molecules.
All the following function in the process of protein synthesis except
A. RNA polymerase.
B. electron transport.
C. cytosine and uracil.
D. amino acids.
The mRNA that codes for a particular protein will have ___ nucleotides for each amino acid in the protein.
The production of RNA using DNA as a template is known as
Transposons are movable genetic elements that
A. carry information for protein synthesis.
B. form copies of themselves which move from the normal position into areas of gene activity.
C. are composed solely of protein.
D. exist only in viruses.
Genes existing on plasmids may include those for
A. bacterial DNA synthesis.
B. capsule production.
C. Krebs cycle enzymes.
D. antibiotic resistance and bacteriocins.
The chromosome of Escherichia coli
A. is a linear chromosome.
B. has about 4300 genes.
C. is surrounded by a membrane.
D. contains some 35,000 genes.
The genome of a bacterium consists of
A. all the structural genes in the chromosome.
B. the complete set of genetic information.
C. all the RNA molecule in a cell.
D. All the proteins in a cell.
The origin of the penicillin-resistant strain Neisseria gonorrhoeae probably is due to
A. infection by a virus.
B. inadequate culture media.
C. spontaneous mutation.
D. nonsense mutation.
Bacteriocins are proteins that
A. inhibit or kill other bacteria.
B. are important to DNA replication.
C. ensure protein fold properly into their tertiary structure.
D. terminate translation.
The tRNA anticodon TTT would pair up with the codon
D. No such anticodon exists.
If a complete bacterial mRNA contains 3000 codons, how many amino acids will exist in the protein produced?
All the following are true of the bacterial chromosome except
A. it is composed of DNA.
B. it contains plasmids.
C. it replicates by the semiconservative method.
D. it is about 1000 times the length of the bacterium
All the following are essential to the process of DNA replication except
A. DNA ligase.
B. Okazaki fragments.
C. DNA polymerase.
Mutations arising from chance events in the environment are known as
A. point mutations.
B. spontaneous mutations.
C. environmental mutations.
D. induced mutation.
The stop codon in a mRNA codes for
A. the last amino acid.
B. a nonsense amino acid.
C. the amino acid methionine.
D. no amino acid.
A new DNA molecule can be produced by
A. conservative replication.
B. a rolling circle mechanism.
C. frameshift replication.
D. generalized transcription.
The point on the chromosome where any particular gene is to be found is referred to as its
A. initiation point.
The enzyme responsible for the synthesis of DNA from a DNA template is
A. DNA polymerase.
B. DNA ligase.
C. DNA synthase.
D. DNA reverse transcriptase.
The passing of genes between parent and offspring is called
B. vertical gene transfer.
C. lateral (horizontal) gene transfer.
Transformation occurs in approximately ______ percent of a bacterial population.
Which one of the following statements does not apply to F plasmids?
A. They are found in F+ cells.
B. They are separate from the bacterial chromosome.
C. They carry genes for essential bacterial metabolism.
D. They are a double-stranded loop of DNA.
An F' plasmid contains a fragment of
A. viral DNA.
B. chromosomal DNA.
C. human DNA.
D. None of the above (A-C) is correct.
During conjugation a recipient cell might be converted to a donor cell by the
A. loss of its capsule.
B. acquisition of the F factor.
C. production of plasmids.
D. inactivation of the lysogenic state.
6. If DNA is transferred laterally from a donor E. coli cell to a recipient Shigella cell, the transfer is called
A. generalized recombination.
D. specific recombination.
Conjugation can occur in gram-positive bacteria if they possess
B. competence factors.
C. a capsule.
D. clumping factors.
The competence of a bacterium refers to its ability to
A. support viral replication.
B. take up DNA from the environment.
C. conjugate with other competent bacteria.
D. change from an F+ cell to an F- cell.
All the following apply to the process of transformation except
A. the recipient's pathogenicity may increase.
B. it occurs in Bacillus species.
C. the recipient incorporates two acquired strands of DNA.
D. R factors may be transferred.
Generalized transduction is carried out by
A. virulent phages that have a lysogenic cycle.
B. temperate phages that undergo lysogeny.
C. virulent phages that have a lytic cycle.
D. temperate phages that are incapable of lysogeny.
A prophage is
A. viral DNA integrated into the bacterial chromosome.
B. a virulent phage that undergoes a lytic cycle.
C. another name for a bacteriophage.
D. a plasmid consisting of viral DNA.
A. is more common than generalized transduction.
B. requires a virulent phage.
C. produces defective phages.
D. can be responsible for human illness.