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105 terms

Micro Midterm

BIO 275, Ch 4-9, Microbiology Cowan 3rd Ed.
STUDY
PLAY
DNA of microorganisms is made up of subunits called
Nucleotides
Base pairs in DNA are held together by ___ bonds.
hydrogen
The enzyme that can proofread replicating DNA, detects incorrect bases, excises them, and correctly replaces them is
DNA polymerase
A permanent, inheritable change in the genetic information is called a
Mutation
A sequence of bases on a gene that does not not code for protein is called an
Intron
Which is incorrect about inducible operons?
have genes turned off by a build up of end product
The lactose repressor___
is inactivated by binding lactose
Bacterial conjugation involves
a donor cell that synthesizes a sex pilus
Which of the following is not a type of bacterial DNA recombination?
Mitosis
The transfer of DNA fragments from a dead cell to live, competent recipient cell that results in a changed recipient cell is ___.
Transformation
A bacteriophage transfers DNA of the previous host to the current host. This is an example of ____.
Transduction
In Griffith's experiments with Streptococcus pneumoniae, rough non-encapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat-killed smooth encapsulated Streptococci. What is the term that describes this process?
Transformation
Repressible operons are normally turned on in the cell.
TRUE
All mutations are not beneficial to the cell.
FALSE
Eukaryotic chromosomes differ from prokaryotic chromosomes because only eukaryotes have ____.
"ALL of the above"
-histone proteins
-chromosomes in a nucleus
-several to many chromosomes
-elongated, not circular, chromosomes
An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a:
Photoautotroph
The term phototroph refers to an organism that:
gets energy from sunlight
The term chemotroph refers to an organism that:
gets energy by oxidizing chemical compounds
The methanogens, producers of methane gas, require environments that:
are anaerobic with hydrogen gas and CO2
Aerobic respiration is an example of
Chemoheterotrophy
Microorganisms that live in severe habitats, such as very hot, acidic, or salty environments, are called:
extremeophiles
The term facultative refers to:
the ability to exist in a wide range of conditions.
Nutrient absorption is mediated by the:
Cell membrane
An organism with a temperature growth range 45-60 deg C would be called a:
Thermophile
An organism that can exist in both oxygen and oxygen-less environments is a:
Facultative anaerobe
An organism that cannot tolerate an oxygen environment is an:
Obligate anaerobe
The time interval from parent cell to two new daughter cells is called the
generation time
The phase of bacterial growth curve in which the rate of multiplication equals the rate of cell death is:
Stationary phase
The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing is the:
Lag phase
The phase of the bacterial growth curve that shows the maximum rate of cell division is the:
Log phase
All of the chemical reactions in a cell are called:
Metabolism
Enzymes
Proteins that function as catalysts
Reactants are converted to products by:
Breaking and forming bonds
Each of the following are true of enzymes except:
they increase the activation energy of a reaction (actually decrease it)
During aerobic cellular respiration, the final electron acceptor is:
Oxygen
Enzymes that are always present, regardless of the amount of substrate are:
Constitutive enzymes
Metabolic pathways that regenerate their starting points are called _____ pathways.
Cyclic
Most electron carriers are:
Coenzymes
In addition to electrons, which of the following is also involved in electron transfer?
Hydrogen
All of the following pertain to glycolysis except:
Degrades glucose to CO2 and H2O
In bacterial cells, the electron transport system is located in the:
Cell membrane
As the electron transport carriers shuttle the electrons, they actively pump _____ into the outer membrane compartment setting up a concentration gradient called the Proton Motive Force.
Hydrogen ions
In which pathway is the most NADH generated?
Krebs cycle
During which phase of cellular respiration is the majority of ATP formed?
Electron transport
Fermentation..
Requires an organic electron acceptor
Filamentous fungi are called
Molds
Which is not characteristic of fungi?
Photosynthetic
The long thread like branching cells of molds are called
hyphae
The woven, intertwining mass of hyphae that makes up the body of a mold is a
Mycelium
Fungal asexual spores
Are used to identify fungi
What two categories of fungi cause human disease?
Primary and opportunistic
Infections caused by fungi are called mycoses.
TRUE
All fungi have hyphae.
FALSE
In humans, fungi can only infect the skin.
FALSE
All fungi cause some kind of disease in plants and animals.
FALSE
Fungi can reproduce both sexually and asexually.
TRUE
Host cells of viruses include:
humans and animals, plants and fungi, bacteria, protozoa, and algae
Viruses:
Cannot be seen in a light microscope
Viral capsids are made from subunits called:
Capsomeres
Viral nucleic acids include which of the following:
Double or single stranded DNA, double or single stranded RNA
The correct sequence of events in viral multiplication is:
Adsorption, penetration, uncoating, synthesis, assembly, release
Host range is limited by:
Type of host cell receptors on cell membrane
The envelope of enveloped viruses is
Obtained by a viral budding or exocytosis
Viruses attach to their hosts via:
Host glycoproteins
The process of dissolving the envelope and capsid to release the viral nucleic acid is:
Uncoating
Which of the following occurs during assembly?
Nucleocapsid is formed and viral spikes insert in host cell membrane
Persistent viruses that can reactivate periodically are:
Chronic latent viruses
What structures are used by bacteriophages to attach to host cell receptors?
Tail fibers
The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is:
Injection of only the viral nucleic acid into the host cell
Lysogeny refers to?
Viral genome inserting into bacterial host chromosome
Viruses that infect bacteria are specifically called:
Bacteriophages
A common method for cultivating viruses in the lab is to use in vitro systems called ____ cultures.
Cell
A ____ is the protein shell around the nucleic acid core.
Capsid
The core of every virus particle always contains?
Either DNA or RNA
In general, most DNA viruses multiply in the host cell's ____, while most RNA viruses multiply in the host cell's __.
Nucleus, cytoplasm
Which of the following is not true of the outer membrane?
Gram positive bacteria have an outer membrane
The function of bacterial endospores is
Protection of genetic material during harsh conditions
Which term is not used to describe bacterial cell shapes?
Tetrad
The outcome of the Gram stain is based on differences in the cell's
Cell wall
The cell envelope or its parts can interact with human tissue and cause disease
TRUE
All bacterial cells have
One or more chromosomes
Syphillis is caused by a spirochete called:
Treponema pallidum
Gram negative bacteria do not have peptidoglycan in their cell walls
FALSE
A prokaryotic cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is
Gram positive
Peptidoglycan is a unique macromolecule found in bacterial
Cell walls
The cell _____ can be composed of three layers: the membrane, the cell wall and the outer membrane.
Envelope
Which of the following species of bacteria is not closely related to the others?
Escherichia coli
Which structure protects bacteria from being phagocytized?
Capsule
Lipopolysaccharide is an important cell wall component of
Gram negative bacteria
Which of the following is not a bacterial class involved in causing human and animal diseases?
Archaebacteria
Bacterial endospores are not produced by
Staphylococcus
The most immediate result of destruction of a cell's ribosomes would be
Protein synthesis would stop
The enzyme _____, that is found in tears and saliva, can hydrolyze the bonds in the glycan chains of certain bacterial cell walls.
Lysozyme
The two functions of bacterial appendages are
Attachment and motility
Plasmids
Are often the site of pathogenic genes
The prokaryotic cell membrane is a site for many enzymes and metabolic reactions.
TRUE
Halobacterium salinarium lives in and requires salt to grow. This is an example of an archaeabacterium described as a(n) __.
Halophile
The chemical components of ribosomes are proteins and
rRNA
The transfer of genes during bacterial conjugation involves rigid, tubular appendages called
Sex pili
The term that refers to the presence of flagella all over the cell surface is
Peritrichous
Both gram-positive and gram-negative cells have outer membranes.
FALSE
Movement of a cell toward a chemical stimulus is termed
Chemotaxis
The site/s for most ATP synthesis in prokaryotic cells is/are the
Cell membrane
Two major structures that allow bacteria to adhere to surfaces are ___ and ___.
Fimbrae, capsules
Lysozyme is most effective against
Gram positive organisms