BISC 101 LAB EXAM QUESTIONS WITH COMPLETE
SOLUTIONS.
Serological Pipette Answer - Used to accurately dispense volumes of liquids
pasteur pipette Answer - Used to dispense liquids when accuracy is less
important , and to gently mix liquid mixtures by pipetting in and out
Preparing wet mounts on glass slides Answer - To spread a sample thin enough
( between a glass slide and a glass cover slip) to view clearly under a
microscope
A simple chemical test : Using Iodine to test for starch Answer - To determine
whether a sample contains starch
Starch= plant/veggies
No starch = animals
Cheesecloth and funnel filter instructions Answer - Used to filter out larger
solids while allowing liquids and smaller particles ( eg. Cells, organelles, etc) to
pass through
how do molecules pass the membrane Answer - active/facilitated transport,
selective permeability of lipid bilayer, and concentration gradient
compound microscope Answer - Used to view objects at 40x 100x or 400x
magnification - to see cells
,spectrophotometer Answer - Used to measure how much light ( of each
specific wavelength/colour) is absorbed by a sample. A prism is used to split
the light, so that you can test one wavelength at a time across a wider range of
possible wavelengths
eppendorf/IEC centrifuge Answer - Used to separate the particles within a
mixture into layers according to their relative densities, by spinning the mixture
at extremely high speeds. The densest particles are found at the bottom of the
table
Independent variable Answer - The variable that is manipulated and its effect
on the dependent variable is measured
Hypertonic Answer - When the concentration of solute is greater outside than
inside, water flows out= causes cell to shrivel and shrink in size
Hypotonic Answer - When the concentration of solute is greater inside the cell
than outside, water flows in= causes cell to swell and burst
isotonic Answer - when the concentration of both the solute and solvent is
equal so theres no net movement
What happens when you put a cell into a hypotonic solution? Answer - fills to
almost bursting
what happens when you put a cell into a hypertonic solution Answer - shrivels
what happens when you put a cell into an isotonic solution Answer - normal
, the cell membrane is permeable to Answer - Small hydrophobic molecules ( ex.
O2, CO2 , N2 , Benzene)
Small uncharged molecules ( ex. H2O, glycerol)
the cell membrane is not permeable to Answer - Large, uncharged molecules
(ex. Glucose, sucrose)
Ions (ex. Cl-, K + , Na+)
why does Increasing the temperature increases the membrane permeability
Answer - o When raising the temperature, its fluidity increases, the atoms
move faster including those that make up the phospholipid bilayers .
o This causes the membrane to be more fluid since the phospholipids are also
moving and that it can be easily penetrated by other molecules
Why do you think a solute's solubility affects its ability to cross the RBC
membrane ? Answer - o A solutes solubility in oil affect its ability to cross the
RBC membrane helps determine its polarity. Since Water is polar and oil is non
polar , it means that the molecules are not attracted to each other. Thus, the
more soluble in oil it is, the more polar the solute is.
What color are the P atoms in 3D molecule of DNA? what is phosphorus
bonded to, to make a phosphate group? Answer - - Purple
attached to the 5 carbon sugar at the 5th carbon (opposite to nitrogenous base
/react-text
- it is made up of a P with 4O bonded to it to make a phosphorus group
What is the colour of the nitrogen atoms, Answer - -Blue
-N is bonded to the first carbon of the 5 carbon molecule
SOLUTIONS.
Serological Pipette Answer - Used to accurately dispense volumes of liquids
pasteur pipette Answer - Used to dispense liquids when accuracy is less
important , and to gently mix liquid mixtures by pipetting in and out
Preparing wet mounts on glass slides Answer - To spread a sample thin enough
( between a glass slide and a glass cover slip) to view clearly under a
microscope
A simple chemical test : Using Iodine to test for starch Answer - To determine
whether a sample contains starch
Starch= plant/veggies
No starch = animals
Cheesecloth and funnel filter instructions Answer - Used to filter out larger
solids while allowing liquids and smaller particles ( eg. Cells, organelles, etc) to
pass through
how do molecules pass the membrane Answer - active/facilitated transport,
selective permeability of lipid bilayer, and concentration gradient
compound microscope Answer - Used to view objects at 40x 100x or 400x
magnification - to see cells
,spectrophotometer Answer - Used to measure how much light ( of each
specific wavelength/colour) is absorbed by a sample. A prism is used to split
the light, so that you can test one wavelength at a time across a wider range of
possible wavelengths
eppendorf/IEC centrifuge Answer - Used to separate the particles within a
mixture into layers according to their relative densities, by spinning the mixture
at extremely high speeds. The densest particles are found at the bottom of the
table
Independent variable Answer - The variable that is manipulated and its effect
on the dependent variable is measured
Hypertonic Answer - When the concentration of solute is greater outside than
inside, water flows out= causes cell to shrivel and shrink in size
Hypotonic Answer - When the concentration of solute is greater inside the cell
than outside, water flows in= causes cell to swell and burst
isotonic Answer - when the concentration of both the solute and solvent is
equal so theres no net movement
What happens when you put a cell into a hypotonic solution? Answer - fills to
almost bursting
what happens when you put a cell into a hypertonic solution Answer - shrivels
what happens when you put a cell into an isotonic solution Answer - normal
, the cell membrane is permeable to Answer - Small hydrophobic molecules ( ex.
O2, CO2 , N2 , Benzene)
Small uncharged molecules ( ex. H2O, glycerol)
the cell membrane is not permeable to Answer - Large, uncharged molecules
(ex. Glucose, sucrose)
Ions (ex. Cl-, K + , Na+)
why does Increasing the temperature increases the membrane permeability
Answer - o When raising the temperature, its fluidity increases, the atoms
move faster including those that make up the phospholipid bilayers .
o This causes the membrane to be more fluid since the phospholipids are also
moving and that it can be easily penetrated by other molecules
Why do you think a solute's solubility affects its ability to cross the RBC
membrane ? Answer - o A solutes solubility in oil affect its ability to cross the
RBC membrane helps determine its polarity. Since Water is polar and oil is non
polar , it means that the molecules are not attracted to each other. Thus, the
more soluble in oil it is, the more polar the solute is.
What color are the P atoms in 3D molecule of DNA? what is phosphorus
bonded to, to make a phosphate group? Answer - - Purple
attached to the 5 carbon sugar at the 5th carbon (opposite to nitrogenous base
/react-text
- it is made up of a P with 4O bonded to it to make a phosphorus group
What is the colour of the nitrogen atoms, Answer - -Blue
-N is bonded to the first carbon of the 5 carbon molecule
