MIC 102 CORE EXAM SET 2025/2026 QUESTIONS AND
ANSWERS GRADED A+
✔✔Positive - ✔✔Left-handed supercoiling
✔✔Negative - ✔✔Right-handed supercoiling
✔✔DNA Gyrase - ✔✔- Supercoils DNA from positive --> negative using energy
- unwinds supercoils caused by replisome
- untangles fully replicated chromosome
✔✔Reverse Gyrase - ✔✔Supercoils DNA from negative --> positive using energy
✔✔Topoisomerase - ✔✔Allows DNA to relax, does not use energy
✔✔Nucleoid-Cytoplasm Interface - ✔✔- interior of nucleoid excludes ribosomes
- when genes are transcribed, they are unspooled at the surface of the nucleoid for RNA
translation
- controls where/when translation occurs
✔✔Gas Vesicle - ✔✔- common among aquatic photosynthetic microbes
- tune buoyancy for optimal light gathering
- protein shell permeable to gas, impermeable to water
✔✔Thylakoids - ✔✔- increase membrane SA of photosynthetic bacteria
- increases light-gathering abilities
✔✔Carboxysomes - ✔✔- used in bacteria that perform carbon fixation w/ CO2
- enhance function of RuBisCo
- allows necessary reactions to continue without O2 poisoning
✔✔Storage Granules - ✔✔- storage of useful materials when in abundance
- Sulfur, Calcium, Phosphorus
- bright spot in cell under a microscope = probably a storage granule
✔✔Magnetosomes - ✔✔- membrane-bound iron-containing stuctures
- acts as a compass to orient during motility
- attached to cell membrane
✔✔a - ✔✔Which of these is NOT found in any prokaryotic cell?
a. Storage granules containing DNA
b. Plasmids that are stably inherited
c. Coexisting thylakoids and carboxysomes
d. Gas vesicles and carboxysomes surrounded by protein shells
, e. Circular DNA with regulated supercoiling
✔✔b - ✔✔The smallest genome among bacteria would probably belong to:
a. A bacterium capable of metabolizing a wide variety of compounds to gather energy
and building materials.
b. bacterium that lives inside of a host cell.
c. A bacterium living in a deep ocean thermal vent.
d. A bacterium living in the soil.
✔✔Autotroph - ✔✔Obtains carbon from carbon dioxide
✔✔Chemolithotroph - ✔✔Obtains energy from sulfide
✔✔Heterotroph - ✔✔Gets energy and carbon from glucose
✔✔Phototroph - ✔✔Gets energy and carbon from sunlight, can grow without being fed
building blocks
✔✔Binary Fission - ✔✔- exponential growth
- 1 cell --> 2 cells --> 4 cells, etc.
✔✔Minimal Medium - ✔✔only contains materials absolutely necessary for basic growth
✔✔Rich Medium - ✔✔contains components allowing for high growth rates
✔✔Defined Medium - ✔✔every component for growth and its quantity are known
✔✔Undefined Medium - ✔✔some components or quantities for growth are unknown
✔✔Turbidity - ✔✔- measure amount of light passing through a culture
- more bacteria = more light scattered
- reported as optical density or absorbance
- cells scatter light whether they're alive or not
✔✔Viable Cell Count - ✔✔- only count living and reproducing cells
- dilute culture, spread onto a plate, assume that only living cells will form colonies
✔✔Direct Cell Count - ✔✔- load samples into counting chamber, count total number
- can't distinguish between living and dead
- time-consuming
✔✔Flow cytometry - ✔✔- count cells directly with laser detector
- count cells with specific features
- very expensive
ANSWERS GRADED A+
✔✔Positive - ✔✔Left-handed supercoiling
✔✔Negative - ✔✔Right-handed supercoiling
✔✔DNA Gyrase - ✔✔- Supercoils DNA from positive --> negative using energy
- unwinds supercoils caused by replisome
- untangles fully replicated chromosome
✔✔Reverse Gyrase - ✔✔Supercoils DNA from negative --> positive using energy
✔✔Topoisomerase - ✔✔Allows DNA to relax, does not use energy
✔✔Nucleoid-Cytoplasm Interface - ✔✔- interior of nucleoid excludes ribosomes
- when genes are transcribed, they are unspooled at the surface of the nucleoid for RNA
translation
- controls where/when translation occurs
✔✔Gas Vesicle - ✔✔- common among aquatic photosynthetic microbes
- tune buoyancy for optimal light gathering
- protein shell permeable to gas, impermeable to water
✔✔Thylakoids - ✔✔- increase membrane SA of photosynthetic bacteria
- increases light-gathering abilities
✔✔Carboxysomes - ✔✔- used in bacteria that perform carbon fixation w/ CO2
- enhance function of RuBisCo
- allows necessary reactions to continue without O2 poisoning
✔✔Storage Granules - ✔✔- storage of useful materials when in abundance
- Sulfur, Calcium, Phosphorus
- bright spot in cell under a microscope = probably a storage granule
✔✔Magnetosomes - ✔✔- membrane-bound iron-containing stuctures
- acts as a compass to orient during motility
- attached to cell membrane
✔✔a - ✔✔Which of these is NOT found in any prokaryotic cell?
a. Storage granules containing DNA
b. Plasmids that are stably inherited
c. Coexisting thylakoids and carboxysomes
d. Gas vesicles and carboxysomes surrounded by protein shells
, e. Circular DNA with regulated supercoiling
✔✔b - ✔✔The smallest genome among bacteria would probably belong to:
a. A bacterium capable of metabolizing a wide variety of compounds to gather energy
and building materials.
b. bacterium that lives inside of a host cell.
c. A bacterium living in a deep ocean thermal vent.
d. A bacterium living in the soil.
✔✔Autotroph - ✔✔Obtains carbon from carbon dioxide
✔✔Chemolithotroph - ✔✔Obtains energy from sulfide
✔✔Heterotroph - ✔✔Gets energy and carbon from glucose
✔✔Phototroph - ✔✔Gets energy and carbon from sunlight, can grow without being fed
building blocks
✔✔Binary Fission - ✔✔- exponential growth
- 1 cell --> 2 cells --> 4 cells, etc.
✔✔Minimal Medium - ✔✔only contains materials absolutely necessary for basic growth
✔✔Rich Medium - ✔✔contains components allowing for high growth rates
✔✔Defined Medium - ✔✔every component for growth and its quantity are known
✔✔Undefined Medium - ✔✔some components or quantities for growth are unknown
✔✔Turbidity - ✔✔- measure amount of light passing through a culture
- more bacteria = more light scattered
- reported as optical density or absorbance
- cells scatter light whether they're alive or not
✔✔Viable Cell Count - ✔✔- only count living and reproducing cells
- dilute culture, spread onto a plate, assume that only living cells will form colonies
✔✔Direct Cell Count - ✔✔- load samples into counting chamber, count total number
- can't distinguish between living and dead
- time-consuming
✔✔Flow cytometry - ✔✔- count cells directly with laser detector
- count cells with specific features
- very expensive
