CSMLS Exam Questions with Correct Answers 100% Verified By Experts|2025/2026 Latest
Update
What molecule is responsible for HOW living organsims synthesize energy?` DNA
What are the 2 divisions of metabolism? Catabolism and Anabolism
What is the function of ATP? Stores energy for metabolism
What are the four phases of a bacterial growth curve? Lag, Exponential, Stationary and
Death
Define Sterilization The destruction of all microbial life
Define Disinfection The destruction of microbial life on an inanimate object
Define Antisepsis The destruction of microbial life on living tissue (endospores may survive)
What is level 1 control of precautions? Standard precautions - everyone should follow.
What are level 2 control of precautions? Contact Precautions - when a patient is infected
and you can garb up to protect yourself because the infection can be spread with direct contact
What are level 3 control of precautions? Droplet Precautions - patient can spread the
infection through droplets
What are level 4 control of precautions? Airborne/ Isolation precautions. Can be spread
because microorganisms can survive and "fly" in air.
,Vertical Gene Transfer Genetics passed on through reproduction
Horizontal Gene Transfer Transferring genes to another microbe of the same generation
(sets microbes away from multi-celled life)
What are the three mechanisms of horizontal gene transfer? Transformation
Conjugation
Transduction
How can horizontal gene transfer change microorganisms? Microbes can become more
virulent and drug resistant which would make the disease harder to treat
Transduction Genetic material passes via a bacterial virus known as a bacteriophage
Transformation Bacteria bind DNA from there surroundings (DNA could be floating due to
lysis)
Conjugation Donor contracts recipient through a sex pilis. This results in both cells having
identical copies of the genetic material
Transposition DNA pieces can hop to new locations on a genome
How can genetic diversity be studied? By analyzing the sequence of nucleotides in rRNA
What type of ribosomes are in eukaryotic cells? 80S
What kind of ribosomes are within prokaryotic cells 70S
,Clone vs. Strain Clone is a population of cells derived from a single cell
Strain is genetically different cells within a clone
How are wavelength and resolution related in microscopy? As the wavelength decreases,
resolution increases.
Resolution To see 2 points as separate and distinct
What does it mean if a microscope has a resolving power of 0.4 nm? That the microscope
can distinguish 2 points 0.5 nm apart
Refractive Index The light bending ability of a medium (light may bend too much and miss
the high magnification lens)
Low refractive index = high resolution
What is the purpose of Immersion Oil Is used to keep light from bending
What light is collected in Bright field Microscopes? Both light reflected from the object and
unreflected lightq
What light is collected in Darkfeild Microscopes? Only the light reflected from the object.
An opaque disc UNDER the condenser blocks out light that would otherwise enter the objective
directly.
What is the purpose of Phase-Contrast Microscopy Allows for detailed examination of
internal structures of non-fixed and unstained specimens
, In-Phase vs. Out of Phase In phase = peaks match and troughs match = adds light waves
together
Out of phase = peaks and troughs do not match up = cancels light waves out showing black in
the specimen since there is no light.
How does Florescent Microscopy work? Florescent substances adsorb UV light and emit
visible light. They luminesce.
What is immunofluorescence? With the use of a fluorochrome labelled AB in the diagnosis
of a specific infectious disease
How can specimens be fixed to a slide before staining? With heat or methyl alcohol
Why do Acid- Fast bacteria retain the red carbolfuscin dye? Because they have a waxy layer
of mycolic acid. The dye is more soluble in the lipid layer of the bacteria instead of the acid
alcohol reagent
Psychrophiles Prefer 0-20oC. They live in cold regions of the world and are not associated
with human disease
Thermophiles Cannot grow at body temp (body temp is too low)
Mesophiles Human pathogens. They grow at 20-40oC
What makes up ambient air Naturally occurring gases in the air we breathe.
21% O2
Update
What molecule is responsible for HOW living organsims synthesize energy?` DNA
What are the 2 divisions of metabolism? Catabolism and Anabolism
What is the function of ATP? Stores energy for metabolism
What are the four phases of a bacterial growth curve? Lag, Exponential, Stationary and
Death
Define Sterilization The destruction of all microbial life
Define Disinfection The destruction of microbial life on an inanimate object
Define Antisepsis The destruction of microbial life on living tissue (endospores may survive)
What is level 1 control of precautions? Standard precautions - everyone should follow.
What are level 2 control of precautions? Contact Precautions - when a patient is infected
and you can garb up to protect yourself because the infection can be spread with direct contact
What are level 3 control of precautions? Droplet Precautions - patient can spread the
infection through droplets
What are level 4 control of precautions? Airborne/ Isolation precautions. Can be spread
because microorganisms can survive and "fly" in air.
,Vertical Gene Transfer Genetics passed on through reproduction
Horizontal Gene Transfer Transferring genes to another microbe of the same generation
(sets microbes away from multi-celled life)
What are the three mechanisms of horizontal gene transfer? Transformation
Conjugation
Transduction
How can horizontal gene transfer change microorganisms? Microbes can become more
virulent and drug resistant which would make the disease harder to treat
Transduction Genetic material passes via a bacterial virus known as a bacteriophage
Transformation Bacteria bind DNA from there surroundings (DNA could be floating due to
lysis)
Conjugation Donor contracts recipient through a sex pilis. This results in both cells having
identical copies of the genetic material
Transposition DNA pieces can hop to new locations on a genome
How can genetic diversity be studied? By analyzing the sequence of nucleotides in rRNA
What type of ribosomes are in eukaryotic cells? 80S
What kind of ribosomes are within prokaryotic cells 70S
,Clone vs. Strain Clone is a population of cells derived from a single cell
Strain is genetically different cells within a clone
How are wavelength and resolution related in microscopy? As the wavelength decreases,
resolution increases.
Resolution To see 2 points as separate and distinct
What does it mean if a microscope has a resolving power of 0.4 nm? That the microscope
can distinguish 2 points 0.5 nm apart
Refractive Index The light bending ability of a medium (light may bend too much and miss
the high magnification lens)
Low refractive index = high resolution
What is the purpose of Immersion Oil Is used to keep light from bending
What light is collected in Bright field Microscopes? Both light reflected from the object and
unreflected lightq
What light is collected in Darkfeild Microscopes? Only the light reflected from the object.
An opaque disc UNDER the condenser blocks out light that would otherwise enter the objective
directly.
What is the purpose of Phase-Contrast Microscopy Allows for detailed examination of
internal structures of non-fixed and unstained specimens
, In-Phase vs. Out of Phase In phase = peaks match and troughs match = adds light waves
together
Out of phase = peaks and troughs do not match up = cancels light waves out showing black in
the specimen since there is no light.
How does Florescent Microscopy work? Florescent substances adsorb UV light and emit
visible light. They luminesce.
What is immunofluorescence? With the use of a fluorochrome labelled AB in the diagnosis
of a specific infectious disease
How can specimens be fixed to a slide before staining? With heat or methyl alcohol
Why do Acid- Fast bacteria retain the red carbolfuscin dye? Because they have a waxy layer
of mycolic acid. The dye is more soluble in the lipid layer of the bacteria instead of the acid
alcohol reagent
Psychrophiles Prefer 0-20oC. They live in cold regions of the world and are not associated
with human disease
Thermophiles Cannot grow at body temp (body temp is too low)
Mesophiles Human pathogens. They grow at 20-40oC
What makes up ambient air Naturally occurring gases in the air we breathe.
21% O2
