Straighterline BIO 202L
Lab 1-Lab 18 questions
bank with 100% correct
answers 2026
Lab 4 Diffusion and Osmosis BIO201L
Student Name: Kris&e Vasquez
Access Code (located on the lid of your lab kit): AC-41swxr
Lab Report Format Expecta0ons
U"lize college level grammar and professional forma4ng when
comple"ng this worksheet.
Submissions without proper forma4ng, all required photos or sufficient
responses will be rejected. Prelab Ques>ons
1. Define the following terms.
a. hypertonic solu&on:
A hypertonic solu&on is one that has a higher
concentra&on of solutes (such as salts, sugars, or proteins)
compared to another solu&on, par&cularly when
comparing two solu&ons separated by a semipermeable
membrane. In the context of biology, when a cell is placed
in a hypertonic solu&on, water tends to move out of the cell
to the surrounding solu&on to balance the solute
concentra&ons, which can lead to cell shrinkage.
, b. hypotonic solu&on:
A hypotonic solu&on, in contrast, has a lower
concentra&on of solutes compared to another solu&on
across a semipermeable membrane. In this scenario, if a cell
is placed in a hypotonic solu&on, water will tend to move
into the cell, poten&ally causing the cell to swell and, in
extreme cases, burst due to the influx of water.
c. isotonic solu&on:
An isotonic solu&on has an equal concentra&on of solutes
as another solu&on across a semipermeable membrane. In
this case, there is no net movement of water into or out of
the cell, and the cell remains in a state of equilibrium with
its environment
2. Define osmo&c pressure.
Osmo&c pressure is the pressure that is required to stop the net
movement of water across a
semipermeable membrane. It is a measure of the tendency of a
solvent, typically water, to move into a solu&on due to
differences in solute concentra&ons. In biological systems, osmo&c
pressure is crucial in maintaining proper cell func&on and
volume.
3. Explain what would happen to a cell placed in a hypertonic
solu&on.
When a cell is placed in a hypertonic solu&on, it will experience
osmosis, where water moves out of the cell and into the
surrounding solu&on to balance the higher solute concentra&on
outside the cell. This leads to a decrease in cell volume and can
cause the cell to shrink, a process known as crena&on in red
, blood cells, or plasmolysis in plant cells. This loss of water can be
detrimental to cell func&on and viability.
EXPERIMENT 1: DIFFUSION THROUGH
A LIQUID Introduc>on Ques>ons
1. State the molecular weight of the blue dye in grams per mole.
793 g/mole
2. State the molecular weight of the red dye in grams per mole.
496 g/mole
3. Why does this experiment require two dyes of different molecular
weights? Answer this ques&on, ensuring you explain the purpose
of these two dyes in rela&on to the experiment. Experiments
that involve size-exclusion of dye molecules require two dyes of
different molecular weights to demonstrate the principle of size
exclusion chromatography. Size-exclusion chromatography is a
method that separates molecules based on their size and is
widely used for protein purifica&on and analyzing the molecular
weight distribu&on of complex samples. In such an experiment,
when a mixture of dyes is passed through a column containing a
porous matrix, small molecules enter the pores and take longer
to elute, while larger molecules are excluded and elute quicker.
, Data and Observa>ons
Record the diameters you observed for both dyes in the table below.
Table 1: Rate of Diffusion in Corn Syrup
Time Blue Red
(sec) Dye Dye
10 0.1cm 1cm
20 0.5cm 1.5cm
30 0.7cm 1.5cm
40 0.9cm 1.6cm
1cm 1.7cm
50
60 1.1cm 1.7cm
70 1.1cm 1.8cm
80 1.3cm 1.8cm
90 1.3cm 1.9cm
100 1.3cm 2cm
110 1.4cm 2cm
120 1.4cm 2cm
Lab 1-Lab 18 questions
bank with 100% correct
answers 2026
Lab 4 Diffusion and Osmosis BIO201L
Student Name: Kris&e Vasquez
Access Code (located on the lid of your lab kit): AC-41swxr
Lab Report Format Expecta0ons
U"lize college level grammar and professional forma4ng when
comple"ng this worksheet.
Submissions without proper forma4ng, all required photos or sufficient
responses will be rejected. Prelab Ques>ons
1. Define the following terms.
a. hypertonic solu&on:
A hypertonic solu&on is one that has a higher
concentra&on of solutes (such as salts, sugars, or proteins)
compared to another solu&on, par&cularly when
comparing two solu&ons separated by a semipermeable
membrane. In the context of biology, when a cell is placed
in a hypertonic solu&on, water tends to move out of the cell
to the surrounding solu&on to balance the solute
concentra&ons, which can lead to cell shrinkage.
, b. hypotonic solu&on:
A hypotonic solu&on, in contrast, has a lower
concentra&on of solutes compared to another solu&on
across a semipermeable membrane. In this scenario, if a cell
is placed in a hypotonic solu&on, water will tend to move
into the cell, poten&ally causing the cell to swell and, in
extreme cases, burst due to the influx of water.
c. isotonic solu&on:
An isotonic solu&on has an equal concentra&on of solutes
as another solu&on across a semipermeable membrane. In
this case, there is no net movement of water into or out of
the cell, and the cell remains in a state of equilibrium with
its environment
2. Define osmo&c pressure.
Osmo&c pressure is the pressure that is required to stop the net
movement of water across a
semipermeable membrane. It is a measure of the tendency of a
solvent, typically water, to move into a solu&on due to
differences in solute concentra&ons. In biological systems, osmo&c
pressure is crucial in maintaining proper cell func&on and
volume.
3. Explain what would happen to a cell placed in a hypertonic
solu&on.
When a cell is placed in a hypertonic solu&on, it will experience
osmosis, where water moves out of the cell and into the
surrounding solu&on to balance the higher solute concentra&on
outside the cell. This leads to a decrease in cell volume and can
cause the cell to shrink, a process known as crena&on in red
, blood cells, or plasmolysis in plant cells. This loss of water can be
detrimental to cell func&on and viability.
EXPERIMENT 1: DIFFUSION THROUGH
A LIQUID Introduc>on Ques>ons
1. State the molecular weight of the blue dye in grams per mole.
793 g/mole
2. State the molecular weight of the red dye in grams per mole.
496 g/mole
3. Why does this experiment require two dyes of different molecular
weights? Answer this ques&on, ensuring you explain the purpose
of these two dyes in rela&on to the experiment. Experiments
that involve size-exclusion of dye molecules require two dyes of
different molecular weights to demonstrate the principle of size
exclusion chromatography. Size-exclusion chromatography is a
method that separates molecules based on their size and is
widely used for protein purifica&on and analyzing the molecular
weight distribu&on of complex samples. In such an experiment,
when a mixture of dyes is passed through a column containing a
porous matrix, small molecules enter the pores and take longer
to elute, while larger molecules are excluded and elute quicker.
, Data and Observa>ons
Record the diameters you observed for both dyes in the table below.
Table 1: Rate of Diffusion in Corn Syrup
Time Blue Red
(sec) Dye Dye
10 0.1cm 1cm
20 0.5cm 1.5cm
30 0.7cm 1.5cm
40 0.9cm 1.6cm
1cm 1.7cm
50
60 1.1cm 1.7cm
70 1.1cm 1.8cm
80 1.3cm 1.8cm
90 1.3cm 1.9cm
100 1.3cm 2cm
110 1.4cm 2cm
120 1.4cm 2cm
