Plants as producers perform the process of photosynthesis. Chlorophyll is the molecule – key to photosynthesis. What happens on a planet without enough light? Why the leaves of plants, are green? Are they green on any other planet? To answer all these questions we studied the chlorophyll. With the spectroscope we saw that absorbs red and blue, and reflects the green. With a clever experiment – game showed why the sky on Earth is blue and we associated this fact with the behavior of chlorophyll. We studied the growth of plants under radiation of different wavelengths, as well as in conditions of limited or poor lighting

1. What color would plants have on
another planet?

2. Introductory section and preparatory phase
• Short Description: Plants as producers perform the process of
photosynthesis. Chlorophyll is the molecule – key to photosynthesis. What
happens on a planet without enough light? Why the leaves of plants, are
green? Are they green on any other planet? To answer all these questions
we studied the chlorophyll. With the spectroscope we saw that absorbs
red and blue, and reflects the green. With a clever experiment – game
showed why the sky on Earth is blue and we associated this fact with the
behavior of chlorophyll. We studied the growth of plants under radiation of
different wavelengths, as well as in conditions of limited or poor lighting.
• Keywords: Chlorophyll, photosynthesis, spectroscopy, plants, polarized
light, blue sky, color adsorption.
• Target audience: Students studying Natural Sciences (especially
Physics, Biology, Chemistry and Astronomy)
• Age range: 14-18 years old
• Context: Natural Sciences School Lab, Computer School Lab, internet
connection.
• Time required: 6 hours (preparation), 1-2 months for full project.

3. Introductory section and preparatory phase
• Technical Requirements: Fully equipped Natural Sciences Lab, Internet
connection, Microsoft Office, Microsoft Windows, Computers, video projector
could be useful.
• Author’s background: Knowledge of Physics, Chemistry, Biology and
Astronomy. The project is mainly based on astrobiology and co-evolution of life
in other planets. Photosynthesis, plants grow up, chlorophyll, light physics,
polarization and optics are main science topics related to our project.
• Connection with the curriculum: Strongly related with Astronomy (Second
Class of Greek High School), Physics (First, Second and Third Class of Greek
High School) Biology (Second Class of Greek High School). Partly related with
Chemistry (First Class of Greek High School).
• Learning Objectives: Hands on learning, Inquiry based learning, connection
between Universities-Institutes and Schools, use of Open Science Resources,
learn students to cooperate and act as researchers.
• Guidance for preparation: Study the biology of photosynthesis, the chemistry
of chlorophyll reactions and physics of light. Observe polarization of light, the
plants color and relate the green color of plant leaves with the blue color of the
sky. Plant lentils and expose the plants under high and low light, and under
color filters. Study the growth of plants under no sunny light.

4. Pre-Experiment / Observation– Teaching Phase 1:
Questions Eliciting Activities – PROVOKE CURIOSITY
Teacher asks students why do they believe the leaves of the plants are
green (and not black for instance)?
Teacher asks students why sky is blue?
Teacher presents to students the following video:
https://www.youtube.com/watch?v=HIwOSbH8yD8&list=FLYcVaeaC8X
YOprtynu9iRgQ

5. Pre-Experiment / Observation– Teaching Phase 1:
Questions Eliciting Activities – DEFINE QUESTIONS FROM
CURRENT KNOWLEDGE
• The role of chlorophyll in
photosynthesis:
(http://en.wikipedia.org/wiki/Photosynt
hesis )
• Photosynthesis:
(http://www.youtube.com/watch?v=g7
8utcLQrJ4 )
• The wavelengths of chlorophyll’s adsorption.
http://www.youtube.com/watch?v=WYKBEYRkh
Lg

6. Pre-Experiment / Observation– Teaching Phase 2: Active
Investigation – PROPOSE PRELIMINARY EXPLANATION OR
HYPOTHESES
• Why sky is blue?
• Scattering of light into
atmosphere.
• Why during daytime sky is blue,
whether at dawn and evening is red?
•Students are modeling the scattering
procedure, following a clever game.

7. Pre-Experiment / Observation– Teaching Phase 2:
Active Investigation – PLAN AND CONDUCT SIMPLE
INVESTIGATION
• Students are asked to extract chlorophyll from spinach leaves (boiling
spinach, stirring mixture of boiled spinach with ethanol, filtered the
green suspension in test-tube and add gasoline, chlorophyll emerges
in surface).
• Students are observing
the adsorption spectrum,
comparing it with a
continuous one.

8. Pre-Experiment / Observation– Teaching Phase 2:
Active Investigation – PLAN AND CONDUCT SIMPLE
INVESTIGATION
• Students are asked to study the chemical
compound that gives the green color in plants by
techniques of chromatography (purring green
leaves of spinach in acetone, mark filter paper,
immerse the marked filter paper into the test-tube
carrying amount of acetone
•Students are observing the two areas of
different colour, green and yellow,
corresponding to chlorophylls and
carotenoids, respectively.

9. Experiment / Observation– Teaching Phase 3:
Creation – GATHER EVIDENCE FROM OBSERVATION
• Students are asked to demonstrate the direct correlation of leave
color to atmosphere colors. To study the behavior of chlorophyll
students plant lentils in irrigated cotton and let it sprout in
controlled conditions. We have lentils grown in poor lighting
(absolute darkness), lentils grown in greenhouse conditions of
glass and lentils under color filters (red, green, blue).

10. Experiment / Observation– Teaching Phase 4:
Discussion – EXPLANATION BASED ON EVIDENCE
• Students are asked observe the growth rates of the plants
(lentils) under different color filters.
• Also students asked to study the growth rates of plants growing
in greenhouse.

11. Experiment / Observation– Teaching Phase 4:
Discussion – CONSIDER OTHER EXPLANATIONS
• Additionally, students can study the growth of another plant
(e.g. wheat) growing under greenhouse conditions (high
CO2 concentration) and open air (low CO2 concentration)

12. Experiment / Observation– Teaching Phase 4:
Discussion – CONSIDER OTHER EXPLANATIONS
• Finally, the most interesting finding is the color of plants in
total darkness. Plants developed in complete darkness
showed white stem in contra version to illuminated ones,
that showed Green:

13. Post-Experiment / Observation– Teaching Phase 5:
Reflection – COMMUNICATE EXPLANATION
• Students can now compare their findings with “white”
plants in depth oceans with poor lighting conditions.

14. • As follow up activities, students can continue their experiments
with more accurate and precise conditions (strictly defined color
filters) and new experimental objects (e.g. algae).
Post-Experiment / Observation– Teaching Phase 5:
Reflection – FOLLOW UP ACTIVITIES AND MATERIALS

15. • Furthermore, students can suggest astronauts (e.g. Timothy
Peak) to perform such experiments in ISS.
Post-Experiment / Observation– Teaching Phase 5:
Reflection – FOLLOW UP ACTIVITIES AND MATERIALS

16. Contact Information
• Name Surname: Ioannis Chiotelis
• Affiliation: www.pelopio-lykeio.gr
• Address: Arakinthou 20, 26226, Patras, Greece
• Telephone: +306948372341
• Email: johnchiotelis@yahoo.gr
johnchiotelis@gmail.com
johnchiotelis@icloud.com
http://johnchiotelis-yperlepth-yfh.blogspot.gr/