Biol 107 Lab exam Verified Questions
And Elaborations
What is a pure culture? Verified Elaborations A pure culture is an isolated group of
genetically identical cells. (also known as colony).
unit conversions: Verified Elaborations 1m= 100cm= 1000mm= 1E6μm= 1E9nm
What are the three lenses in a light microscope? Verified Elaborations 1) condenser
lens- focuses the light from underneath onto the specimen.
2) objective lens- magnifies the image.
3) occular lens (eyepiece) - magnifies the image and inverts it.
Light Microscope (bright field) terminology Verified Elaborations Diaphragm- controls
the amount of light entering the lens system. Less light can improve contrast (the
difference between light and dark areas).
Stage.
The total magnification of the microscope is equal to...? Verified Elaborations The
product of the ocular lens (usually 10X) and the objective lens.
What is resolution? Verified Elaborations The capacity to distinguish between two
adjacent points. Eg) if resolution= 3μm, we are capable of distinguishing two objects
that are 3μm or more apart as being two different objects.
What is a hypotonic solution? Verified Elaborations One where the solute concentration
is higher inside the cell, the cell will fill with water and become turgid.
What is a hypertonic solution? Verified Elaborations One where the solute concentration
is higher outside the cell, so the cell will lose its water and become plasmolyzed.
The steps involved in the scientific method: Verified Elaborations 1) formulate an idea or
question.
2) Formulate a hypothesis (educated guess) that is based on prior knowledge.
3) Test the hypothesis- this can be done by observation or experimentation, or both.
The independent variable is the one that is manipulated, the dependent variable is the
one being measured.
4) draw a conclusion based on the results. Say "supports", not "proves".
* A theory is a very well proven and accepted hypothesis.
What is flaccid? Verified Elaborations Cell than is neither turgid nor plasmolyzed, this
occurs in isotonic cells.
, What is the tonoplast (beta vulgaris)? Verified Elaborations The tonoplast is the
membrane surrounding the central vacuole that contains the betacyanin. The
betacyanin must also pass throught the plasma membrane.
What is absorbance and turbidity? Verified Elaborations Absorbance is when particles
absorb light.
Turbidity is when particles scatter light.
Betacyanin.... Verified Elaborations Maximally absorbs light at 525nm so this is what we
set the spec to.
What is transmittance (T) Verified Elaborations Transmittance refers to the ratio of
transmitted light (light leaving the sample) to incident light (light striking the sample),
therefore it is expressed as a percentage.
What is optical density? Verified Elaborations OD refers to the measurement of light that
gets absorbed or scattered (not transmitted).
What is absorbance? Verified Elaborations It is simply the negative log of transmittance.
How is the standard curve used to help us calculate concentrations? Verified
Elaborations We use a stock solution of betacyanin and dilute it to different
concentrations. Then we create a standard curve where absorbance is linearly
proportional to concentration. Then we can compare the leakage in beta vulgaris to this
standard curve to find the unknown concentrations.
*standard curve CANNOT be extrapolated.
What is the concentration for dilution? Verified Elaborations Dilution= V of original
solution/ V of original solution + V of solvent.
Example: 0.5 mL of original solution in 4.5 mL of solvent = 1 in 10 dilution (or 0.1).
What is the equation for converting concentration of diluted sample (obtained from the
standard curve), into the undiluted concentration? Verified Elaborations Cu= Cd / D
If bacteria are sensitive to a specific antibiotic then there will be a _____ of ______ on
the agar plate Verified Elaborations zone of inhibition.
What do antibiotics do? Verified Elaborations Prevent the growth of bacteria and or
fungus. They do this in different ways- some block cell wall formation, some block
protein synthesis etc.
What cell motility processes are microtubules involved in? Verified Elaborations Flagella
and cilia motion. They are the part of the cytoskeleton that usually allows for organelle
movement. They are also compression resistant.
And Elaborations
What is a pure culture? Verified Elaborations A pure culture is an isolated group of
genetically identical cells. (also known as colony).
unit conversions: Verified Elaborations 1m= 100cm= 1000mm= 1E6μm= 1E9nm
What are the three lenses in a light microscope? Verified Elaborations 1) condenser
lens- focuses the light from underneath onto the specimen.
2) objective lens- magnifies the image.
3) occular lens (eyepiece) - magnifies the image and inverts it.
Light Microscope (bright field) terminology Verified Elaborations Diaphragm- controls
the amount of light entering the lens system. Less light can improve contrast (the
difference between light and dark areas).
Stage.
The total magnification of the microscope is equal to...? Verified Elaborations The
product of the ocular lens (usually 10X) and the objective lens.
What is resolution? Verified Elaborations The capacity to distinguish between two
adjacent points. Eg) if resolution= 3μm, we are capable of distinguishing two objects
that are 3μm or more apart as being two different objects.
What is a hypotonic solution? Verified Elaborations One where the solute concentration
is higher inside the cell, the cell will fill with water and become turgid.
What is a hypertonic solution? Verified Elaborations One where the solute concentration
is higher outside the cell, so the cell will lose its water and become plasmolyzed.
The steps involved in the scientific method: Verified Elaborations 1) formulate an idea or
question.
2) Formulate a hypothesis (educated guess) that is based on prior knowledge.
3) Test the hypothesis- this can be done by observation or experimentation, or both.
The independent variable is the one that is manipulated, the dependent variable is the
one being measured.
4) draw a conclusion based on the results. Say "supports", not "proves".
* A theory is a very well proven and accepted hypothesis.
What is flaccid? Verified Elaborations Cell than is neither turgid nor plasmolyzed, this
occurs in isotonic cells.
, What is the tonoplast (beta vulgaris)? Verified Elaborations The tonoplast is the
membrane surrounding the central vacuole that contains the betacyanin. The
betacyanin must also pass throught the plasma membrane.
What is absorbance and turbidity? Verified Elaborations Absorbance is when particles
absorb light.
Turbidity is when particles scatter light.
Betacyanin.... Verified Elaborations Maximally absorbs light at 525nm so this is what we
set the spec to.
What is transmittance (T) Verified Elaborations Transmittance refers to the ratio of
transmitted light (light leaving the sample) to incident light (light striking the sample),
therefore it is expressed as a percentage.
What is optical density? Verified Elaborations OD refers to the measurement of light that
gets absorbed or scattered (not transmitted).
What is absorbance? Verified Elaborations It is simply the negative log of transmittance.
How is the standard curve used to help us calculate concentrations? Verified
Elaborations We use a stock solution of betacyanin and dilute it to different
concentrations. Then we create a standard curve where absorbance is linearly
proportional to concentration. Then we can compare the leakage in beta vulgaris to this
standard curve to find the unknown concentrations.
*standard curve CANNOT be extrapolated.
What is the concentration for dilution? Verified Elaborations Dilution= V of original
solution/ V of original solution + V of solvent.
Example: 0.5 mL of original solution in 4.5 mL of solvent = 1 in 10 dilution (or 0.1).
What is the equation for converting concentration of diluted sample (obtained from the
standard curve), into the undiluted concentration? Verified Elaborations Cu= Cd / D
If bacteria are sensitive to a specific antibiotic then there will be a _____ of ______ on
the agar plate Verified Elaborations zone of inhibition.
What do antibiotics do? Verified Elaborations Prevent the growth of bacteria and or
fungus. They do this in different ways- some block cell wall formation, some block
protein synthesis etc.
What cell motility processes are microtubules involved in? Verified Elaborations Flagella
and cilia motion. They are the part of the cytoskeleton that usually allows for organelle
movement. They are also compression resistant.
