6th Edition By Connie Mahon
The peptidoglycan layer in the Gram negative cell wall is - ANSWER:thin
Bacterial plasmids - ANSWER:carry virulence related genes
do not have housekeeping genes
are circular DNA molecules
Pilli are present in gram positive bacteria only, while flagella are present in Gram
negative bacteria only - ANSWER:false
The F plasmids in bacteria have an essential role in - ANSWER:initiating bacterial
conjugation
The duplication of a DNA molecule in bacteria always starts at the position called -
ANSWER:origin of replication
replication fork
HIV is NOT diagnosed by - ANSWER:cell culture
Sterilisation is - ANSWER:Is the killing or removal of all viable organisms - bacteria
spores and viruses
Which is not a physical factor used in Sterilization - ANSWER:disinfection
Genetic transformation in microbes - ANSWER:can be demonstrated in infected
laboratory animals such as mice
is easier in competent cells
can occur when a bacteriophage infects a bacterial cell
occurs when DNA is incorporated into a recipient cell and leads to genetic changes
Microbial transduction - ANSWER:is the packaging of bacterial DNA inside a newly
formed bacteriophage molecule
A segment of DNA that can move from one site to another on the same or a different
DNA molecule is called - ANSWER:transposable element
Bacterial endotoxins are - ANSWER:cellular components released upon cell lysis
Integral membrane proteins are - ANSWER:firmly embedded in the cytoplasmic
membranes of bacterial cells
, The prokaryotic ABC transport system - ANSWER:is not a simple transport system
requires energy in the form of ATP molecules
is often involved in the uptake of organic compounds and inorganic nutrients
displays high substrate specificity
5-Bromouracil is - ANSWER:a nucleotide base analogue
A microbial cell can contain more than one plasmid, but they must be -
ANSWER:from different incompatibility groups
Most areas of skin including sweat glands are colonised with Gram negative bacteria
- ANSWER:False
the skin is colonised mostly with G+ve bacteria
The lower respiratory tract lacks microflora in healthy individuals - ANSWER:true
E. coli and P. mirabilis frequently cause - ANSWER:urinary tract infections in women
Invasiveness - ANSWER:Can cause damage without producing a toxin
is the ability of a pathogen to grow in host tissue at densities that inhibit host
function
Staphylococcal alpha toxin has both cytolytic and hemolytic activities - ANSWER:true
this toxin kills nucleated cells and also lyses erythrocytes
Supercoiling is important for DNA structure, because - ANSWER:it condenses the
DNA so that it can fit inside the cell
Which of the following statements is INCORRECT regarding mutations in bacterial
cells? - ANSWER:Mutations are NOT immediately expressed because the bacterial
cell is diploid
The most critical step in the use of 16Sr RNA sequence data in phylogenetic studies is
- ANSWER:Matching the gene sequence to the sequences in the reference data bank
In bacterial cytoplasmic membranes - ANSWER:hydrophilic portions remain exposed
to external environment or to cytoplasm
fatty acids point inward to form a hydrophobic environment