Microbiology - chapter 8
A gene is best defined as
a sequence of nucleotides in DNA that codes for a functional product
Which of the following statements about DNA is TRUE
a) DNA polymerase joins nucleotides in one direction only
b) The leading strand of DNA is made continuously
c) the lagging strand of DNA is started by an RNA primer
d) multiple replication forks are possible on a bacterial chromosome
DNA is constructed of
two strands of nucleotides running antiparellel
Which of the following is NOT a product of transcription
a new strand o DNA
Which of the following is a product of transcription
a) rRNA
b) tRNA
c) mRNA
Which of the following about bacteriocins are TRUE
a) the genes coding for them are on plasmids
b) Nisin is a bacteriocin used as food preservative
c) they can be used to identify certain bacteria
d) bacteriocins kill bacteria
When glucose is high, cAMP is _______: CAP ________bind the lac operator, and RNA polymerase _____ bind the lac promoter
cAMP is low
CAP does not
RNA polymerase does not
Transformation is the transfer fo DNA from a donor to a recipient cell
as naked DNA in solution
Genetic change in bacteria can be brought about by
a) mutation
b) conjugation
c) transduction
d) transformation
Which of the following regarding a bacterium that is R+ is True
a) It possesses a plasmid
b) R+ can be transferred to a cell of the same species
c) it is resistant to certain drugs and heavy metal
d) R+ can be transferred to a different species
The initial effect of ionizing radiation on a cell is
the formation of highly reactive ions
According to the operon model, for the synthesis of an inducible enzyme to occur, the
substrate must bind to the repressor
Synthesis of a repressible enzyme is stopped by the
corepressor-repressor complex binding to the operator
The damage caused by ultraviolet radiation is
cut out and replaced
Conjugation differs from reproduction because conjugation
transfers DNA horizontally, to cells in the same generation
if you mix the DNA polymerase Thermus aquaticus and the template from human cell. The DNA synthesized would be most similar to
human DNA
An enzyme that makes covalent bonds betwwen nucleotide sequences in DNA is
DNA ligase
An enzyme that copies DNA to make a molecule of RNA is
RNA polymerase
An enzyme that catalyzes the cutting and resealing of DNA, and is translated from insertion sequences is
transposase
Repair of damage DNA might be viewed as a race between an endonuclease and
methylase
The miRNAs in a cell
allow different cells to produce different proteins
Protein synthesis in eukaryotes is similar to the process in prokaryotes in that both
use codons to determine polypeptide sequences
Recombination will always alter a cell's genotype
TRUE
Bacteria contain multiple chromosomes
FALSE
Mutation that are harmful to cells occur more tan those that benefit cells
TRUE
Some organisms contain multiple genomes
FALSE
Both base substitution and frameshift mutations can result in the formation of premature stop codon
TRUE