Quiz Questions From Class (all) Flashcards
Which of the following organisms does not always divide in a separate plane but instead has random division planes causing a cluster like arrangement
Staphylococcus epidermidis
Some bacteria are considered pleomorphic, which means they have no defined shape. The reason some bacteria are pleomorphic is due to
The lack of a cell wall
Which of the following best describes Archaea domain of life
Prokaryotes living in environments of extreme temperature, pH, or other unusual environmental conditions
The cell membranes of archaebacteria are different from cell membranes of eubacteria by all of the following except
They are protein-based instead of lipid base to increase stability
The true phylogenetic tree of life which divides organisms into three domains eubacteria, archaea and eukarya is based on
The relatedness of 16 S ribosomal RNA genetic sequences
How does bacterium control the direction of motility
The bacteria stops and randomly spins if not going in the right direction
The third amino acid in the peptidoglycan cross-linking chain is either lysine or a modified form of lysine known as diaminopimilic acid because this amino acid must
Have a free amino group on the R side chain to form a peptide bond
Which of the following is not true about capsules and slime layers?
They are absolutely required for growth on laboratory media
Lipopolysaccharide consists of three parts. One component is always found in LPS and is toxic. Another component is variable and can be used for stain classification of some organisms. The toxic component is______ and the variable component is_____.
Lipid A; oligosaccharide.
What is the purpose of bacterial endospores
Allow bacterium to survive harsh conditions
You cell is moving towards an attractant by a chemotaxis mechanism. If the concentration gradient decreases, then
The methyl group is removed from MCP
Based on your knowledge of prokaryotic cells, eukaryotic cells, and virus structure. Which of the organisms in table above is not a virus
Based on your knowledge of virus structure. Which of the organisms in the table above would rely on a budding mechanism of release from an infected cell.
Organism A
Organism C
Which of the following is not a major factor contributing to the durability of bacterial spores
Dipicolinic acid
The purpose of this molecule is too slow virus particle movement so that they do not pass directly through a host, but find their primary receptor
Low affinity receptor
Most plant viruses penetrate the host cell by
Injection of the genome through the cell wall
Microbial growth is measured by what parameter?
Increase in total number of cells
Reduction in numbers of pathogenic organisms so that they do not pose a disease threat
Sanitation
Your instructor has you culturing Bacillus sterothermophilus, but you forgot which incubator to place the cultures in. You look around the lab and see several incubators. Which do you think should be used
The incubator at 65 C
An organism that expends energy to grow in a habitat with low-water activity and high solute activity in order to maintain internal solute concentrations to retain water is
Osmophile
Which would kill the greatest percentage of cells
A. A D100 value of 10 minutes
B. A D100 value of 5 minutes
C. Both would kill the same percentage of cells
C. Both would kill the same %of cells.
You prepare test tubes containing solid auger media. The concentration of oxygen at the surface of the auger media is normal, but gradually decreases to O at the bottom of the test tube….
Obligate aerobe; facultative anaerobe
Cold sterilization refers to the use of
Ionizing radiation
You isolate the following enzymes from an unknown organism—superoxide dismutase and catalase. You can conclude that this organism is probably
An aerobic
Which of the following would not sterilize
Alcohol
All of the following statements pertain to phenol except
It has a mild smelling older, and no detrimental effects on the skin
The chemical counterpart of the autoclave uses
Ethylene oxide with an inert gas
If you were cleaning benches or tables on which you would be placing patients with exposed skin, you would probably want to use a disinfectant such as
Alcohol
Quaternary ammonium compounds (quats) are a type of
Detergent
Cell wall inhibiting antibiotics block the synthesis of new cell wall formation such that actively growing bacteria will not have complete walls. Based on this idea at what point in the bacterial growth curve are bacteria the most vulnerable to these antibiotics?
Lag phase