Life of a Leaf: Teacher Handout
All 3 activities have been adapted and slightly modified from several online resources, in which
the websites are listed. A more simplified version of these activities was put together for the Lab
at the North Carolina Museum of Life and Science.
North Carolina Standards:
3.L.2.1 Remember the function of the following plant structures as it relates to the survival of
plants in their environment: (Roots – absorb nutrients; Stems – provide support; Leaves –
synthesize food; Flowers – attract pollinators and produce seeds for reproduction 5D/E3b)
6.L.1.2. Explain the significance of the processes of photosynthesis, respiration and transpiration
to the survival of green plants and other organisms.5A/M2
6.L.2.1 Summarize how energy derived from the sun is used by plants to produce sugars
(photosynthesis) and is transferred within food chains and food webs (terrestrial and aquatic)
from producers to consumers to decomposers. 5E/1
Purpose
Describe the shape of a leaf
Examine how the leaf makes food for the plant
Extract chlorophyll and other pigments from leaves
Observe the parts of a leaf and hypothesize their functions
Background
The leaf is often the primary above-ground organ of most plants. Many leaves tend to be flat,
although some may seem thicker from their ability to store water (e.g. succulence). Leaves also
come in many shapes, sizes, degree of hairiness or smoothness, waxiness, colors, and venation.
These differences are often thought to be adaptations to the environment to maximize surface
area for photosynthesis and to minimize damage from elements such as the wind, herbivores, UV
light, and desiccation.
The main function of a leaf is to perform photosynthesis, the process in which the chlorophyll
and other components in the chloroplasts use energy from sunlight to convert carbon dioxide and
water into sugars and oxygen. The carbon dioxide enters through specialized pores called the
stomata, which can open and close. However, water can also exit through these pores in a
process known as transpiration. This causes a tradeoff between obtaining carbon and losing
water. These pores are also sites where the oxygen that is produced can exit so that humans can
breathe it.
Safety
Do not look directly into the UV light!
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Part I: Leaf Shape Diversity
Time allocation:
This can be a 50 min activity (especially for 3rd graders) if you decide to collect leaves during
the class period or a 15-20 minute activity if you (or your students) decide to collect leaves prior
to the class period.
Adapted from these sources:
Project Learning Tree – Looking at Leaves: https://www.plt.org/family-activities-looking-atleaves
https://www.nwf.org/kids/family-fun/outdoor-activities/leaf-match.aspx
http://www.rabbitsabc.com/leaves.html
http://www.kidzsearch.com/wiki/Leaf
http://www.connectionsacademy.com/resources/instructographics/a-leaf-science-activity-for-kids
Materials
 Crayons with the paper part torn off– two colors per student
 Ruler
 Leaves – two per student
o Some suggestions: Oak, Pine, Maple, Willow, Ash, Poplar, Grass, Rose,
Magnolia, Fern
o Options – you can do an outdoor activity where the students walk around the
school to pick some leaves. You can also have students just pick leaves from their
garden, around the school campus, etc. Make sure that they store the leaves in a
plastic bag and put it in the fridge so the leaves are fresh.
Note: You do not need to know the tree/plant it comes from (if you do, great!),
but the point is to get students to realize that there is a diversity of leaf shapes
around them and to take a closer look at them.
 Printout of leaf shapes (one per pair of students; this can be reused for each class):
o Leaf arrangement (can use this one first for everything else. If students are up for
a challenge, they can use the other sheets as well):
https://www.britannica.com/science/alternate-leaf-arrangement/imagesvideos/Common-leaf-morphologies/374
o Leaf shape: http://plant-life.org/glossary/leaf_configs1.htm
o Leaf venation: http://levasseurr082.angelfire.com/images/venation_chart.jpg
o Leaf margin:
http://www.clemson.edu/extension/natural_resources/landowner/youth_environ_e
ducation/images/leaf_margins.gif
Procedure
1. Choose 2 leaves.
2. Place the handout over the leaf.
3. Use a crayon to color and rub over the leaf to make an imprint.
4. Using the handouts, ask the students to describe the leaf.
5. Ask the students to share this with their partners.
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6. Optional challenge (especially if they get to go outside and pick leaves): see which group
of students (if a group of 4) can make rubbings of the most diverse leaves. For every
different type of arrangement, shape, margin, and venation, they get a point.
Further Explanation
Here, we have a variety of leaf shapes, some having a few lobes (like the maple leaf), others are
narrow and thin (like the willow), or some are thin as needles (like pine leaves). Although leaves
can be found on almost all plants, these ones are come from trees.
Transition
What is the purpose of a leaf? Have you heard about plants making their own food? What do
plants need to survive?
Air, water, sun
How does it absorb light? We will extract the compound that uses the light.
Part II: Chlorophyll extraction
Time allocation:
For part A: ~10-15 minutes
For part B: ~30-60 minutes
Adapted from these sources:
http://www.scientificamerican.com/article/bring-science-home-leaf-colors/
http://www.backyardbiology.net/Nature_Activities/LeafChromatography.shtml
http://www.compoundchem.com/wp-content/uploads/2014/09/Chemistry-of-Autumn-Leaves2015.png
Materials (per student group)
 Any type of leaves (especially leaves that change colors, like maple and oak). Use
spinach leaves as a backup
 1 bottle of Rubbing Alcohol
 3-5-mL transfer pipet
 2 clear plastic cups
 Coffee filter (white)
 Sandwich plastic bag
 UV light/black light
 Ruler
 2 Pencils
 Tape
 Quarter
Preparation
 Pour rubbing alcohol stock into beakers for each student group.
 Cut coffee filters into 1” strips.
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Procedure
Part A:
1. Give each group of students two leaves.
2. Tear the leaves into smaller pieces into the plastic bag.
3. Add rubbing alcohol (about 5 squirts with the transfer pipet) into the plastic bag with the
leaf. Remove as much air from the bag and close the plastic bag.
4. Mash the leaf and the rubbing alcohol.
5. Open up the bag. Use the transfer pipet and transfer the liquid into a plastic cup.
6. The teacher will turn off the classroom lights. She/he will come around with a UV light
and shine it into the mixture.
Chlorophyll absorbs most visible light, except for green, which is why most leaves appear
green to us. When chlorophyll is exposed to UV light, energy from the light will be reemitted as red light, also know as chlorophyll fluorescence.
Part B:
1. Give each pair of students 2 strips of coffee filter paper. Using a pencil, draw a
horizontal line about 1.5 inches from the bottom (see diagram on the side) for
each coffee filter strip. Label them 1 and 2.
Draw line here, about 1.5
inches from the bottom.
2. Fill one other cup with some rubbing alcohol (about 5 squirts with a transfer pipet).
3. Tape the filter paper to a pencil. Adjust the length of the filter paper as needed such that
the line on the filter paper does not go below the liquid.
4. Place filter paper #1 into the cup with the chlorophyll extraction mixture from Part I. The
filter paper should dangle off of the pencil and into the cup. Look at the below diagram
(from http://www.preproom.org/_images/practicals/leaf_chromatography1_l.jpg):
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5. For filter paper #2, put a leaf (spinach, or any other leaf) over the line on the filter paper.
Using a quarter (or any coin), rub the leaf over the line on the filter paper. Do this
multiple times.
6. Place filter paper #2 into the cup with the rubbing alcohol.
7. Leave the filter paper in the solution for an hour to overnight and observe the separation
the next day.
Example above from http://pulpbits.net/wp-content/uploads/2013/12/Spinach-Leaf-Pigments.jpg
However, your actual filter papers might look different. This is because a different solvent
(mobile phase: not rubbing alcohol) and a different “paper” (stationary phase; not filter paper)
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may have been used to separate out the different pigments in the leaves. It also can be that there
is very little separation of the pigments.
Further Explanation
Chlorophyll is a specific pigment that absorbs light energy. There are several types of
chlorophyll, and there are other pigments found in the leaf. These pigments can be separated out
using a process known as paper chromatography. Each pigment sticks to the paper with different
affinities, which results in the pigments separating out into distinct layers on a piece of paper.
The light energy absorbed can undergo 3 different processes. 1) It can undergo photosynthesis;
2) it can dissipate as heat; 3) it can be re-emitted as light, or chlorophyll fluorescence. Because of
these possibilities, measuring chlorophyll fluorescence is an indirect way of measuring
photosynthesis and plant stress.
Transition
The chlorophyll absorbed the light, but how does the air get in?
Station Three: Leaf Anatomy – Stomata and Chloroplasts
Time Allocation: 30 minutes
Teacher preparation time: 30 min – 1 hour
Adapted from:
https://www.exploratorium.edu/imaging_station/activities/classroom/elodea_explorations/ca_elo
dea_explorations.php
https://www.teacherspayteachers.com/Product/Leaf-Structure-Stomata-Lab-1941670
http://www.hometrainingtools.com/a/microscope-experiments
http://phdnthesinglemom.blogspot.com/2014/10/epidermal-leaf-slides.html
http://dtc.pima.edu/blc/1004thed/004/004_Leaves_Stomata/stomata.html
http://www.microbehunter.com/using-clear-nail-polish-to-make-impressions-of-plant-leaves/
http://www.saps.org.uk/secondary/teaching-resources/299-measuring-stomatal-density
Materials (per student group)
 Light microscope
 Elodea (from http://www.carolina.com/aquatic-plants/elodea-densa-living-pack-of12/162101.pr?question)
 Broccoli rape, geraniums, cabbage and any other leaf (but spinach does not work well)
 Razor blade (for teacher use only!)
 2 glass slides of leaves (made by teacher)
 Cover slips (for the slides)
 Forceps
 Clear nail polish
 Clear masking tape
 Cutting board
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
Print out of a diagram of a leaf cross-section so that they can attempt to label their
drawings (includes some videos):
https://www.pathwayz.org/Tree/Plain/CROSS+SECTION+OF+A+LEAF+%5BBASIC%
5D
http://kids.britannica.com/comptons/art-53561/Cross-section-of-a-leaf#cite
Preparation
 Make a slide with a layer of nail polish imprint of the epidermis of a leaf (see below)
 Make slides of a cross-section of a leaf. To do this:
o Make thin slices of a leaf using a razor blade, parallel to the line shown in the
image below.
o Place a few thin slices on a glass slide.
o Two options: 1) you can put a droplet of water on top of leaf section and put a
cover slip over it or 2) you can put a piece of clear masking tape over it.
 Make slides of an Elodea leaf. To do this:
o Pick off an Elodea leaf.
o Place the leaf on the slide. Add a drop or two of water over the leaf.
o Cover the leaf with a glass cover slip.
o You can watch this to show how to prepare a slide and to see what to expect with
an Elodea leaf: https://www.youtube.com/watch?v=b6_SuhG_VPM
Procedure
1. Take a leaf, and put a layer of nail polish on the leaf. Put it aside.
2. Take another leaf with an already dried layer of nail polish on it.
3. Take piece of masking tape. Put the tape over the nail polish, and remove the tape.
4. Put the tape with the nail polish layer on a glass slide.
5. Put the slide under a microscope. What do they see?
6. Look at slides with cross-sections of leaves AND Elodea. Can you see where the
chloroplast (chlorophyll) are mostly located?
This probably will be difficult to see depending on the slide preparations. However, if it
is clear, the important thing to notice is that chloroplasts (which contain chlorophyll) are
usually contained the mesophyll cells. For the Elodea, it should be very clear to notice
that all of the green circles are chloroplasts, which all contain chlorophyll.
Further Explanation
Air (carbon dioxide and oxygen) enters through stomata, which can open and close. Water can
also leave via stomata. Many stomata are located on the bottom surface of the leaf, but some can
be found on the top surface as well.
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Conclusion
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


Leaves have diverse shapes, many of which are adapted to their environments.
One of the main functions of a leaf is to perform photosynthesis, which is the process of a
plant to use the sun, air (carbon dioxide), and water to make food and oxygen.
The plant absorbs light using chlorophyll, which are found in chloroplasts.
The plant obtains air through specialized pores called stomata.
References
Wikipedia articles (actually not too bad)
https://en.wikipedia.org/wiki/Photosynthesis
https://en.wikipedia.org/wiki/Chlorophyll
https://en.wikipedia.org/wiki/Chlorophyll_fluorescence
Websites
http://cnx.org/contents/W7ctJeSI@8/Overview-of-Photosynthesis
https://www.khanacademy.org/science/biology/photosynthesis-in-plants/introduction-to-stagesof-photosynthesis/a/intro-to-photosynthesis
http://scienceaid.co.uk/biology/biochemistry/photosynthesis.html
http://www.ucmp.berkeley.edu/glossary/gloss3/pigments.html
http://www.chm.bris.ac.uk/motm/chlorophyll/chlorophyll_h.htm
https://www2.estrellamountain.edu/faculty/farabee/biobk/BioBookPS.html
https://www.khanacademy.org/science/biology/photosynthesis-in-plants/introduction-to-stagesof-photosynthesis/v/photosynthesis
Textbook
Taiz, Lincoln; Zeiger, Eduardo (2002). Plant Physiology (3rd ed.). Sunderland, MA: Sinauer
Associates. ISBN 0-87893-823-0.
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