MICROBIOLOGY MIDTERM EXAM QUESTIONS
WITH CORRECT ANSWERS 2025/2026
Define Micro- - CORRECT ANSWER -Less than 1mm and cannot see with the naked eye
Need a microscope to see
Microbes, microorganisms, germs, bugs
What are the 5 groups of microorganisms studied? - CORRECT ANSWER -Bacteria--most famous
Virus--2nd
Fungus--3rd
Protozoa--some but few
Algae--not a human pathogen
What generates 1/2 of the O2 that we breathe and would make life impossible without? -
CORRECT ANSWER -Microbes
What is the smallest simplest single-celled organism? - CORRECT ANSWER -Bacteria
What is not a cell, can't live by itself and needs to invade a cell? - CORRECT ANSWER -Virus
What are the two different classification of fungus? - CORRECT ANSWER -Molds and yeast--
micro
Mushrooms--Macro
What is a mostly single-celled organism that is Animal like? - CORRECT ANSWER -Protozoa
What are parasites? - CORRECT ANSWER -Different organisms that range from worms, insects
and protozoa that need a host to survive
,What are the different applied microbiology fields of study - CORRECT ANSWER -Immunology
Epidemiology--control spread of disease
Food Micro--relationship between bacteria, food and drink
Agriculture Micro--relationship between bacteria and crop
Industrial Micro--microbes to produce vitamins, AA, Enzymes, etc.
Eukaryotic cells are... - CORRECT ANSWER -more complete
Prokaryotic cells are... - CORRECT ANSWER -all micro organisms and lack a nucleus
Characteristics of microorganisms - CORRECT ANSWER -Small size
Unicellular simplicity
High Growth rate
Adaptability
microscope - CORRECT ANSWER -instrument used for enlargement of small objects
simple microscope - CORRECT ANSWER -single lens and a few working parts. not strong
compound microscope - CORRECT ANSWER -2 magnifying lenses, a visible light sours, a
condenser which collects light to direct toward the object
magnification - CORRECT ANSWER -capacity of an optical system to enlarge small objects
ocular lens - CORRECT ANSWER -one we look through. 10X
,objective lens - CORRECT ANSWER -4 different, 4X, 10X, 40X, 100X
What is resoltion? - CORRECT ANSWER -Capacity of optical systems to distinguish or separate 2
adjacent objects/points from each other. represents clarity of image
Types of microscope? - CORRECT ANSWER -Light--visible light, bright field, dark field, phase
contrast, diff interference
Ultraviolet--florescence
Electron--scanning, transmission
what type of microscope do we use in the lab? - CORRECT ANSWER -bright field light
microscope
how does a microscope work? - CORRECT ANSWER -light source is on the bottom. The light
travels from the lamp, hits the condenser lents which collects light and points it toward the
object. the light passes through the objective lens and the real image of the object forms behind
the ocular lens. the image we see is the virtual image after it asses through the ocular lens and
is at the total magnification
Highest magnification for all light microscopes? - CORRECT ANSWER -2,000X and 200 nm
resolution
eubacteria - CORRECT ANSWER -the common bacteria of the 2 types. (-) WITH cell walls, (+)
WITH cell walls, and no cell wall (mycoplasm)
archebacteria - CORRECT ANSWER -less common type of bacteria. do not produce
peptidoglycan and can live in extreme environments
, appendages - CORRECT ANSWER -attached to bacteria on one side, the other side is "free"
motility appendages - CORRECT ANSWER -flagella and axial filaments
flagella - CORRECT ANSWER -for motility and self propulsion. found mostly in gram negative
bacteria. provide a smooth forward movement
structure of flagella - CORRECT ANSWER -made of protein with 3 distinct parts: filament, hook,
basal body (inside and has 4 rings and a rod that rotate)
axial filament - CORRECT ANSWER -wrap around the cell and cause spiral like movements. has
only two parts: a long thin microfibril inserted into a hook.
attachment appendages - CORRECT ANSWER -fimbriae and pili
fimbriae - CORRECT ANSWER -short appendages that allow bacteria to attach to bacteria
pili - CORRECT ANSWER -long appendages are found in gram negative bacteria and are useful
when mating
cell envelope - CORRECT ANSWER -the bacterial surface (glycocalyx), the cell wall, cell
membrane
glycocalyx/bacterial surface - CORRECT ANSWER -this layer is a coating to protect the cell. two
types
slime layer - CORRECT ANSWER -type of glycocalyx that protects bacteria from loss of water and
nutrients and loosely bound to the bacteria
WITH CORRECT ANSWERS 2025/2026
Define Micro- - CORRECT ANSWER -Less than 1mm and cannot see with the naked eye
Need a microscope to see
Microbes, microorganisms, germs, bugs
What are the 5 groups of microorganisms studied? - CORRECT ANSWER -Bacteria--most famous
Virus--2nd
Fungus--3rd
Protozoa--some but few
Algae--not a human pathogen
What generates 1/2 of the O2 that we breathe and would make life impossible without? -
CORRECT ANSWER -Microbes
What is the smallest simplest single-celled organism? - CORRECT ANSWER -Bacteria
What is not a cell, can't live by itself and needs to invade a cell? - CORRECT ANSWER -Virus
What are the two different classification of fungus? - CORRECT ANSWER -Molds and yeast--
micro
Mushrooms--Macro
What is a mostly single-celled organism that is Animal like? - CORRECT ANSWER -Protozoa
What are parasites? - CORRECT ANSWER -Different organisms that range from worms, insects
and protozoa that need a host to survive
,What are the different applied microbiology fields of study - CORRECT ANSWER -Immunology
Epidemiology--control spread of disease
Food Micro--relationship between bacteria, food and drink
Agriculture Micro--relationship between bacteria and crop
Industrial Micro--microbes to produce vitamins, AA, Enzymes, etc.
Eukaryotic cells are... - CORRECT ANSWER -more complete
Prokaryotic cells are... - CORRECT ANSWER -all micro organisms and lack a nucleus
Characteristics of microorganisms - CORRECT ANSWER -Small size
Unicellular simplicity
High Growth rate
Adaptability
microscope - CORRECT ANSWER -instrument used for enlargement of small objects
simple microscope - CORRECT ANSWER -single lens and a few working parts. not strong
compound microscope - CORRECT ANSWER -2 magnifying lenses, a visible light sours, a
condenser which collects light to direct toward the object
magnification - CORRECT ANSWER -capacity of an optical system to enlarge small objects
ocular lens - CORRECT ANSWER -one we look through. 10X
,objective lens - CORRECT ANSWER -4 different, 4X, 10X, 40X, 100X
What is resoltion? - CORRECT ANSWER -Capacity of optical systems to distinguish or separate 2
adjacent objects/points from each other. represents clarity of image
Types of microscope? - CORRECT ANSWER -Light--visible light, bright field, dark field, phase
contrast, diff interference
Ultraviolet--florescence
Electron--scanning, transmission
what type of microscope do we use in the lab? - CORRECT ANSWER -bright field light
microscope
how does a microscope work? - CORRECT ANSWER -light source is on the bottom. The light
travels from the lamp, hits the condenser lents which collects light and points it toward the
object. the light passes through the objective lens and the real image of the object forms behind
the ocular lens. the image we see is the virtual image after it asses through the ocular lens and
is at the total magnification
Highest magnification for all light microscopes? - CORRECT ANSWER -2,000X and 200 nm
resolution
eubacteria - CORRECT ANSWER -the common bacteria of the 2 types. (-) WITH cell walls, (+)
WITH cell walls, and no cell wall (mycoplasm)
archebacteria - CORRECT ANSWER -less common type of bacteria. do not produce
peptidoglycan and can live in extreme environments
, appendages - CORRECT ANSWER -attached to bacteria on one side, the other side is "free"
motility appendages - CORRECT ANSWER -flagella and axial filaments
flagella - CORRECT ANSWER -for motility and self propulsion. found mostly in gram negative
bacteria. provide a smooth forward movement
structure of flagella - CORRECT ANSWER -made of protein with 3 distinct parts: filament, hook,
basal body (inside and has 4 rings and a rod that rotate)
axial filament - CORRECT ANSWER -wrap around the cell and cause spiral like movements. has
only two parts: a long thin microfibril inserted into a hook.
attachment appendages - CORRECT ANSWER -fimbriae and pili
fimbriae - CORRECT ANSWER -short appendages that allow bacteria to attach to bacteria
pili - CORRECT ANSWER -long appendages are found in gram negative bacteria and are useful
when mating
cell envelope - CORRECT ANSWER -the bacterial surface (glycocalyx), the cell wall, cell
membrane
glycocalyx/bacterial surface - CORRECT ANSWER -this layer is a coating to protect the cell. two
types
slime layer - CORRECT ANSWER -type of glycocalyx that protects bacteria from loss of water and
nutrients and loosely bound to the bacteria
