Testing theTesting the PhotosytheticPhotosythetic NeedsNeeds of of

PlantsPlantsBy: Jenna CosseyBy: Jenna Cossey

Undergraduate TTUUndergraduate TTUSecondary Education MajorSecondary Education Major

Emphasis- BiologyEmphasis- Biology

IntroductionIntroduction

Can plants survive better in natural sunlight or in artificial Can plants survive better in natural sunlight or in artificial light?light?

Test two groups of plants: one grown in artificial light, one Test two groups of plants: one grown in artificial light, one grown in natural sunlight.grown in natural sunlight.

To accomplish this I will grow one group of plants indoors To accomplish this I will grow one group of plants indoors with no access to natural sunlight, and grow one group of with no access to natural sunlight, and grow one group of plants in a window sill.plants in a window sill.

I expect that the group of plants with access to natural I expect that the group of plants with access to natural sunlight will grow better.sunlight will grow better.

My hypothesis is that plants with grow most efficiently in My hypothesis is that plants with grow most efficiently in natural lighting conditions.natural lighting conditions.

My null hypothesis is that plants will grow bettter in My null hypothesis is that plants will grow bettter in artificial lighting conditions.artificial lighting conditions.

Literature CitingsLiterature Citings Chaney, William R. 2002. Does Night Lighting Chaney, William R. 2002. Does Night Lighting

Harm Trees? Harm Trees? www.ces.purdue.edu/extmedia/FNR/FNR-FAQ-17.www.ces.purdue.edu/extmedia/FNR/FNR-FAQ-17.pdfpdf

Farabee, M.J. 2007. What is Photosynthesis? Farabee, M.J. 2007. What is Photosynthesis? www.emc.maricopa.edu/faculty/farabee/BIOBK/Biwww.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html_rpmi.htmoBookPS.html_rpmi.htm

Taylor, Maxine. 2002. Taylor, Maxine. 2002. www.essortment.com/all/photosynthesiswww.essortment.com/all/photosynthesis

Rothenberger, Ray R. 1993. Lighting Indoor Rothenberger, Ray R. 1993. Lighting Indoor House Plants. House Plants. www.zone10.com/tech/lighting/plantlighting.htmwww.zone10.com/tech/lighting/plantlighting.htm

Vermaas, Wim. 2007. Vermaas, Wim. 2007. http://photoscience.la.asu.edu/photosyn/educatiohttp://photoscience.la.asu.edu/photosyn/education/photointro.htmln/photointro.html

Photosynthetic ProcessPhotosynthetic Process

A simple diagram: A simple diagram:

Carbon Dioxide + water + photons => glucose + oxygenCarbon Dioxide + water + photons => glucose + oxygen

Light SourcesLight Sources• SunlightSunlight• Incandescent LightIncandescent Light

WHICHWHICH SOURCE? SOURCE?

In order to determine which source of In order to determine which source of light best facilitates photosynthesis, I light best facilitates photosynthesis, I experimented with two test groups, experimented with two test groups, one grown in each source of light one grown in each source of light ( artificial, natural) and recorded the ( artificial, natural) and recorded the growing patterns of each.growing patterns of each.

HypothesisHypothesis

Hypothesis:Hypothesis: Plants exposed to more Plants exposed to more natural light will grow more natural light will grow more efficiently.efficiently.

Null:Null: Plants exposed to more Plants exposed to more artificial light will grow more artificial light will grow more efficiently.efficiently.

Experimental DesignExperimental DesignStep 1:Step 1:State the Problem.State the Problem.

Which source of light best Which source of light best facilitates photosynthesis?facilitates photosynthesis?

Step 2:Step 2:Research the Problem.Research the Problem.

Test a group of plants in artificial Test a group of plants in artificial light and test another group of light and test another group of plants in natural light. Plants plants in natural light. Plants need light to grow, but what need light to grow, but what kind?kind?

Step 3:Step 3:Form a Hypothesis.Form a Hypothesis.

Plants exposed to more natural Plants exposed to more natural light will grow more efficiently.light will grow more efficiently.

Step 4:Step 4:Test the Hypothesis.Test the Hypothesis.

To test this hypothesis I will test To test this hypothesis I will test the growth of plants in both the growth of plants in both natural and artificial lighting natural and artificial lighting conditions. And record their conditions. And record their growth rates.growth rates.

Step 5:Step 5:Draw Conclusions from the Draw Conclusions from the data.data.

The growth rate data will either The growth rate data will either prove or disprove my hypothesis.prove or disprove my hypothesis.

How will I know?How will I know?

In order to determine which source of In order to determine which source of light the plants use best I used both light the plants use best I used both quantitative and qualitative analysis.quantitative and qualitative analysis.(Vermaas 2007)(Vermaas 2007)

I measured the height of the plants at I measured the height of the plants at different intervals of growth.different intervals of growth.

I counted the number of plants I counted the number of plants growing at different intervals, as well growing at different intervals, as well as the number of leaves/flowers on as the number of leaves/flowers on each plant.each plant.

Results?Results?

I expected that the plants with I expected that the plants with access to the natural sunlight would access to the natural sunlight would grow best. grow best.

I also expected that the plants in I also expected that the plants in artificial light would grow, but not as artificial light would grow, but not as abundantly.abundantly.

I confirmed my hypothesis and I confirmed my hypothesis and rejected my null hypothesis.rejected my null hypothesis.

Week 1Week 1 Place the plants in their areas Place the plants in their areas to grow and record starting to grow and record starting data.data.

Week 2Week 2 Observe and record any Observe and record any changes in the plantschanges in the plants

Week 3Week 3 Count and measure plants and Count and measure plants and record the data.record the data.

Week 4Week 4 Observe and record any Observe and record any changes in the plants.changes in the plants.

Week 5Week 5 Observe and record any Observe and record any changes in the plants.changes in the plants.

Week 6Week 6 Count and measure the plants Count and measure the plants and record the data.and record the data.

Week 7 Week 7 Observe and record any Observe and record any changes in the plants.changes in the plants.

Week 8Week 8 Observe and record any Observe and record any changes in the plants.changes in the plants.

Week 9Week 9 Final measurement and Final measurement and counting of plants.counting of plants.

DiscussionDiscussion

Experiment confirmed the results of Experiment confirmed the results of previous experiments.( Rothenberger previous experiments.( Rothenberger 1993)1993)

This allowed me to draw my This allowed me to draw my conclusions.conclusions.

Final DiscussionFinal Discussion

My results rejected my null My results rejected my null hypothesis and confirmed my hypothesis and confirmed my alternative hypothesis.alternative hypothesis.

The plants lighted with natural The plants lighted with natural sunlight grew more efficiently. sunlight grew more efficiently.