PHOTOSYNTHESIS: PHOTOSYNTHESIS: THE EFFECTS OF THE EFFECTS OF

ARTIFICIAL LIGHTING ON ARTIFICIAL LIGHTING ON OXYGEN PRODUCTION OXYGEN PRODUCTION

Jade Ross, Kim Krebs, Geoffrey Gilmore, Kate Gester

The QuestionThe Question

How would different types of artificial light affect the growth rate of plants? Refined: how do different types of artificial

light affect photosynthetic rates (measured in oxygen production)?

The ResearchThe Research

Plants grow best under a full spectrum of visible light

Typical artificial lights are biased towards one side of the visible spectrum or the other Incandescent (regular and halogen) bulbs are

biased towards the red portion Fluorescent bulbs are biased towards the blue

portion Natural growth lights are specially designed to

emulate a large portion of the spectrum

Included one plant not exposed to light as control

Incandescent Light BulbIncandescent Light BulbWorks b y p a s s in g e le c t ric ity th rou g h Tu n g s te n fila m e n tGla s s b u lb to p ro te c t , fille d with Bia s e d towa rd re d

Halogen Light BulbHalogen Light Bulb

Su b s e ct ion of In ca n d e s ce n t Bu lb sWorks in a s im ila r m a n n e r

In e rt Ga s + Ha log e n Ga s – Ha log e n cycle

Re -d e p os it s Tu n g s te n b a ck on to fila m e n t - con s ta n t lig h t ou tp u t (h ig h e r co lor t e m p e ra tu re )

Lig h t is focu s e d – m irrorsProd u ce s m u ch m ore h e a t

Fluorescent Light BulbFluorescent Light Bulb

Th e e le c t ric ity h e a ts m e rcu ry va p or

UV e xcit e s p h os p h or, p rod u ce s vis ib le lig h t

Us u a lly u s e s le s s e n e rg yBia s e d towa rd s th e b lu e e n d of th e s p e ct ru m

Set-UpSet-Up

2 leaves from a tree Place leaves inside bottle with O2 sensor Place bottles inside 4 same-size

cardboard boxes Thread sensor cable through small hole in

back Create hole from which to hang light bulb Seal up box with tape so no light will get

in

ResultsResults

Results (1 – Incan, 2 – Hal, 3 Results (1 – Incan, 2 – Hal, 3 Contol)Contol)

(1 – Halogen, 2 – Control)(1 – Halogen, 2 – Control)

(1 – Incan, 2 – CFL)(1 – Incan, 2 – CFL)

ErrorsErrors

Did not find the species of the plant Equipment could have been faulty Forgot to control for heat variable

(halogen) Lack of experience with equipment

Final ConclusionFinal Conclusion

We can not say anything about our hypothesis, whether or it is proven or disproven

Underestimated how complex photosynthesis and plants’ needs are

Insufficient repetitions