Lab exam 03 Flashcards
What grows on EMB plates?
Gram positive bacteria
Will staphylococcus grow on an EMB plate?
Yes
What type of bacteria is used as a lactose fermenter?
Lactococcus and Enterococcus, GRAM NEGATIVE
Most pathogens are _____philes
mesophiles
What type of bacteria remains after pasteurization
Bacillus
Recombination will always alter a cells genotype True or False?
True
Mutations that are harmful to cells occur more frequently than those that benefit cells.
True
In the Ames test, any colonies that form on the control should be the result of spontaneous mutations.
True
According to the operon model, for the synthesis of an inducible enzyme to occur, the
Substrate must bind to the repressor
A group of enzymes produced in response to the presence of a substrate is called a(n)
Inducible operon
An enzyme that reads DNA to make a molecule of RNA is
RNA polymerase
DNA is constructed of
Two strands of nucleotides running antiparallel
Which of the following is NOT a product of transcription? tRNA, mRNA, A new strand of DNA, rRNA.
A new strand of dna
Conjugation differs from reproduction because conjugation
transfers DNA horizontally, to cells in the same generation.
How does decarboxylation affect the pH of the media?
It increases the pH and it becomes more alkaline
What is the purpose of peptone in the media?
Provides nutrients and energy
The mannitol salt is both ________ and ________.
Selective and differential
The autoclave uses ________ to denature proteins.
Coagulation
Dry heat uses ______ to kill bacteria.
oxidation
Mesophiles prefer the temperature ____ to ____degrees.
20-40
Thermophilic bacteria prefer the temperature _____ to _____.
41-122
What temp do hyperthermophiles prefer?
60 degrees +
What type of bacteria prefer temps at around 20 degrees or less?
Psychrophile
Photoautotrophs use
energy from sunlight, carbon dioxide
Photoheterotrophs use
light energy as their energy source. They also cannot use carbon dioxide as their sole carbon source.
Chemoautotrophs use
inorganic energy sources to synthesize organic compounds from carbon dioxide.
Chemoheterotrophs use
are unable to utilize carbon dioxide to form their own organic compounds. Their carbon source is rather derived from sulfur, carbohydrates, lipids, and proteins.
Ethanol works best as a disinfectant at 100% concentration. True or False
Fase
Halophiles require _____.
Salt
Which microorganism is likely to be the cause for a fresh water trout preserved in salt spoiling?
facultative halophiles
What happens if you tried to do a direct cell count with 25 colonies?
There is a larger margin for error
The Krebs cycle occurs in the _______ in prokaryotes and in the ______ in eukaryotes.
Cytosol in prokaryotes, Mitochondria in eukaryotes
Which of the following is a coenzyme?
NADH
Genetic change in bacteria can be brought about by
transduction
conjugation
transformation
mutation
All are correct
Which of the following statements is FALSE?
Multiple replication forks are possible on a bacterial chromosome.
Prokaryotic cells gets rid of introns in the RNA in the cytoplasm
The lagging strand of DNA is started by an RNA primer.
DNA polymerase joins nucleotides in one direction only.
The leading strand of DNA is made continuously.
DNA polymerase joins nucleotides in one direction only
The damage caused by ultraviolet radiation is
cut out and replaced
A gene is best defined as
a sequence of nucleotides in DNA that codes for a functional product
Transformation is the transfer of DNA from a donor to a recipient cell
As naked DNA in a solution
prostate cancer is probably the result of which kind of mutation?
The cell membranes of all three domains are composed of straight carbon chains attached to glycerol by ester linkage.
False
The highest level in the taxonomic hierarchy is “Kingdom.”
False
When building a cladogram, the length of the horizontal branch is based on the calculated percent similarity between organisms.
True
The deinococci can be categorized as extremophiles.
True
All gram-negative bacteria are classified as proteobacteria.
False
Which of the following statements about archaea is FALSE?
They evolved before bacteria
What is the outstanding characteristic of the Kingdom Fungi?
Members absorb dissolved organic matter
Which of the following is NOT based on nucleic-acid hybridization?
Western blotting
Which of the following statements is a reason for NOT classifying viruses in one of three domains rather than in a fourth domain?
Viruses are not composed of cells
In the scientific name Enterobacter aerogenes, Enterobacter
is the
genus
Phage typing is based on the fact that
Bacterial viruses attack only members of a specific species.
Nucleic acid hybridization is based on the fact that
Pairing between complementary bases occurs.
Which of the following lacks a cell wall?
mycoplasma
Plasmogamy, karyogamy, and meiosis are stages of the protozoal sexual life cycle.
False
Life cycle of trematodes contain cercariae, metacercaria, redia, and sporocysts stages.
True
Both the cellular slime molds and the plasmodial slime molds are members of the phylum Amoebozoa.
True
Glycoprotein spikes are found on the capsids of all viruses.
False
Viruses are the only known infectious agents that are obligatory intracellular parasites.
False
Which of the following statements regarding fungi is FALSE?
Most fungi are pathogenic to humans
Which of the following statements regarding lichens is FALSE?
Lichens are very tolerant to pollution
Which of the following tends to be more complex in a parasitic helminth than in free-living helminths?
Reproductive system
The life cycle of the fish tapeworm is similar to that of the beef tapeworm. Which of the following is the most effective preventive measure?
Cooking fish prior to eating
Which of the following is NOT used as a criterion to classify viruses?
Biochemical test
Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps?
Biosynthesis
A persistent viral infection is one in which
The disease process occurs gradually over a long time
An envelope is acquired during which of the following steps?
Release
