Inquiry Lessons in the
Biology Classroom
Presented by Lindsay Bobo
AP Biology and Regular Biology Teacher
Lakewood High School
LBobo@Lbschools.net
Agenda:
1. Introduction to inquiry
a. An experiment to provide students a model of how to
develop their own experiments
2. Inquiry in biology classrooms
a. Ideas of how to incorporate inquiry into AP Biology or
regular biology classrooms
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Ideas for a Biology Classroom:
1. Factors that affect enzymes
a. AP Biology
i. Steps for the experiment
1. Perform a demonstration of an enzyme reaction.
2. Take a small beaker (50 mL) and fill it with hydrogen
peroxide.
3. Take another beaker (600 mL) and fill it with a package of
yeast, about 400 mL of warm water, and a pinch of sugar.
4. Take a small amount of filter paper (about 1 cm2) and use
forceps to dip the filter paper into the solution of yeast.
5. Then take the filter paper and put it at the bottom of the
beaker of hydrogen peroxide.
6. After releasing the filter paper, time how long it takes the
filter paper to reach the top of the hydrogen peroxide.
ii. What’s happening
1. The yeast contains an enzyme called catalase, which can be
found in lots of living things. This enzyme breaks down
hydrogen peroxide into water and oxygen. The oxygen that
forms causes the filter paper to rise to the surface of the
hydrogen peroxide.
iii. What your students can do
1. Students can take their initial set of observations and create
an experiment to test the factor of their choice.
2. For this particular experiment, I pass out specific factors
that each group has to test (temperature, pH, salinity,
enzyme concentration, and substrate concentration). Once
students receive their factor, they develop everything else
for the experiment.
b. Regular Biology
i. Steps for the experiment
1. Take a small piece of potato (about 2 cm3) and put it on a
Petri dish.
2. Have a dropper bottle of hydrogen peroxide.
3. Have students put 2 drops of hydrogen peroxide on the
potato and observe what happens.
4. Students should see white foam and bubbles start to form.
ii. What’s happening
1. The potato contains the enzyme catalase, which breaks
down hydrogen peroxide into oxygen and water. The
bubbles that form are the oxygen that forms as a result of
the reaction.
iii. What your students can do
1. Students can take this initial set of observations and create
an experiment to test factors that affect enzymes. Some
changes students have made in the past are changing the
type of food, temperature, pH, and hydrogen peroxide.
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2. Most students just make qualitative observations for the
experiment, though a few try to time how long it takes for
them to see bubbles form.
2. Determining the Molarity of a Solution
a. AP Biology
i. Steps for the experiment
1. For each group of students provide beakers full of the
following sucrose solutions (0M, 0.2M, 0.4M, 0.6M, 0.8M,
1.0M) and dialysis tubing. The solutions should not be
labeled with their concentrations.
ii. What’s happening
1. The purpose of this experiment is for students to use the
concept of osmosis to determine the molarity of an
unknown solution.
2. Students should be able to determine that if a sucrose
solution with a high molarity is placed in a dialysis tube
and then submerged in distilled water then more osmosis
will occur than with a sucrose solution with less molarity.
iii. What your students can do
1. Students need to design an experiment to find the molarity
of each solution.
2. Based on experience, most students tend to fill the dialysis
tubes with the unknown solutions and then submerge the
tubes in distilled water.
3. Some students have trouble with the experiment and I
really leave them to their own devices, so at the end some
have a lot of error analysis to complete.
b. Regular Biology
i. Steps for the experiment
1. Give each student a raw egg and have them weigh the egg
on a scale.
2. Then have them submerge the egg in a 400 mL beaker full
of 250 mL of vinegar and leave it overnight. (Be sure to
cover the beaker with aluminum foil to prevent
evaporation.)
3. The next day, students need to re-weigh the egg and
measure how much vinegar solution is in the beaker.
ii. What’s happening
1. For this first part of the experiment, the shell of the egg
gets dissolved by the vinegar and the egg gains weight,
since the egg is hypertonic to the vinegar solution.
2. When students put the egg in other solutions, they should
be able to determine the relative molarity of the solutions
based on whether or not the egg gains or loses weight.
iii. What your students can do
1. Tell students they can choose two more solutions to put the
egg in over the next two days. For each day, students will
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weigh the egg and measure how much of the liquid solution
remains in the beaker.
2. Students will be able to apply the concepts of hypertonic,
hypotonic, isotonic, and osmosis to the experiment.
3. Factors that affect Heart Rate and Blood Pressure
a. AP Biology or Regular Biology
i. Steps for the experiment
1. Show students how to measure their heart rate and blood
pressure.
2. I use the LoggerPro heart rate and blood pressure sensors
for this lab, though it can be done with other materials as
well.
ii. What’s happening
1. Heart rate and blood pressure change depending on
different conditions. The body will work harder under
certain conditions to get oxygen to all parts of the body.
iii. What your students can do
1. Students can develop their own experiment to test how a
factor of their choosing affects heart rate or blood pressure.
2. Students tend to really like this lab. Some factors students
have tried in the past are exercise, scaring each other,
temperature, and body positions (i.e. sitting, standing, lying
down).
4. Factors that affect Cellular Respiration
a. AP Biology or Regular Biology
i. Steps for the experiment
1. Show students how to measure cellular respiration rates in
germinating peas using oxygen or carbon dioxide
LoggerPro sensors.
2. You could set up this lab using a different set up, but I have
found LoggerPro sensors to be the easiest and most
reliable.
ii. What’s happening
1. Germinating peas will undergo cellular respiration,
therefore over time you will see the oxygen levels decrease
and the carbon dioxide levels increase.
2. Although you could really use any live organism with this,
I like to use peas to show students that peas don’t just go
through photosynthesis, but they can go through cellular
respiration as well.
iii. What your students can do
1. Students can test different factors that affect cellular
respiration using the peas and the LoggerPro sensors.
2. Factors students have tested in the past include mashing the
peas, salinity, non-germinating peas, pH, temperature, and
types of organisms.
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5. Factors that affect Photosynthesis
a. AP Biology
i. Steps for the experiment
1. This lab comes from the new AP Biology lab manual. To
see the specific steps for the lab, check out
http://www.elbiology.com/labtools/Leafdisk.html
ii. What’s happening
1. The spinach leaves are undergoing photosynthesis.
2. As the spinach leaves go through the light reactions oxygen
is produced.
3. The oxygen causes the spinach leaves to rise to the top of
the cup.
iii. What your students can do
1. Students can test different factors that affect
photosynthesis.
2. Factors students have tested in the past include the color of
light, light/dark, type of light (i.e. glow sticks),
temperature, pH, and salinity.
6. Factors that affect Transpiration Rates
a. AP Biology
i. Steps for the experiment
1. Have students fill a 10 mL graduated cylinder with water.
2. Then have students cut a plant stem under water and
immediately put it in the graduated cylinder, while staying
under the water the entire time.
3. Take the graduated cylinder and plant out of the water and
pipette some water out so that the water level is at the 10
mL line. Cover the water with a few drops of oil to prevent
evaporation.
ii. What’s happening
1. As the water level goes down, transpiration is occurring.
2. The more water that is lost the more transpiration is
occurring.
iii. What your students can do
1. Students can test different factors that affect transpiration
rates.
2. Factors students have tested in the past include
temperature, light levels, wind, humidity, molarity of the
water, and size of the plant.
3. Since water is lost very slowly, I have students come in the
morning to set up the experiment, then come in every
couple of hours throughout the day to monitor their water
levels. This is not ideal, but this set up is much more
successful then the set up described in the AP Biology lab
manual.
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