Lab Experiment on Lightand Starch Production in Photosynthesis
Light sources of different 'colors' produce different photosynthetic responses but these are not due to the quality of the light per se, but instead the absorption of violet and blue light by carotenoids (including -carotene,and xanthophylls diatoxanthin, diatoxanthin, and diadinoxanthin.) -carotene is known to transfer collected energy to chlorophyll and hence photosystem reaction centers, in an inefficient manner.
Effect of different colors of light on the rate of photosynthesis.
The bottle garden is a close relative of the biosphere: a tiny garden growing inside abottle, a glass sphere, or a demijohn. The main difference is that soil is the maincomponent not water. The container can be kept sealed or opened like a terrarium. Ourswill be more for just plants whereas the terrarium may have animals. These gardens in abottle, can be cured and perfected as a system, they are also very decorative, in fact youcan treat them as a bonsai with not only a single tree, but whole landscapes. A carefullychosen stone becomes a rock, a small plot of moss represents a great prairie. A contorted,little plant is now a hundred year old tree. Maybe a marsh wetlands with peat moss,mushrooms and ferns is more to your liking. Maybe appropriate succulent plants with sandand rocks for a vast desert landscape. The choice is yours. There is no rigid rule aboutbeing either an open or a closed garden. It maybe useful to keep the lid on to retainwater. Or eventually, the plants grow up and need to hang down the outside.
If the container is always sealed, the challenge becomes quite demanding. In fact, it thenis necessary to obtain an equilibrium between plants and animals in order to keep aneffective cycle of substances and energy, but if this is difficult in a predominantlywater environment, it is even more difficult in a just moist environment. So, the gardenhas to contain a moist soil, plants, little animals like terrestrial isopods (i.e.: sowbug, pill bug), earthworms, etc. Plants have to be resistant to high moisture and have asmall size and limited growth. To avoid roots rotten, you can also try to refer tohydroponics and substitute the ground with small sized expanded clay or with gravel. Inthis case you will have more difficulties in hosting animal species, so it will have to beleft open. It is important you place your garden in a cool and well illuminated place, butaway from direct sunlight. Open or closed, a bottle garden is a fascinating thing, and theidea itself of a little and self-sufficient world is fascinating as well. There are peopleso fond of bottle gardens they work at them a long time, taking care of them using longand thin tools and to observe these environments till they imagine to be one of theirinhabitants.
Then choose among these main options:
1 - Opened bottle garden, containing moist ground, plants and possible little animals. Itis suited for people who love taking care of gardens and who have a flair for
the architecture of little wide spaces.
2 - Opened bottle garden, prepared in hydroponics and containing plants. It is suited forthose who tend to forget to water their plants.
3 - Sealed bottle garden, holding moist soil, plants, and some little animals. Thisexercise is suitable for people who are keen on biology and scientific research. They willhave to find appropriate plants and animals suitable for a sealed ecosystem and will haveto achieve the necessary conditions for a long survival. This research, bibliographic inpart and experimental, will keep students happily busy for long time.
The educational value of these little ecosystems is evident. They can be carried out evenin a school, where the teacher will be allowed to illustrate their characteristics topupils and encourage interesting discussions. In the web sites below, you will findimportant practical information in building your bottle gardens.
Terrariums : Miniature Worlds in a Bottle!
BBC online, how to gardening, bottle garden
Un jardin en bouteille
Le terrarium : Un monde miniature dans une bouteille!
Internet keywords: garden bottle jar, jardin bouteille bonbonne.
Figure 28. These xanthophylls (diadinoxanthin and diatoxanthin) are important photosynthesis regulators in zooxanthellae. They also absorb mostly violet and blue light. After Jeffrey et al., 1997.
The Effects of Artificial Light on Bats
The following charts demonstrate the rate of photosynthesis - the relative electron transport rate (rETR) - in a coral when illuminated by various LED light sources described above. Other energy dissipation pathways (NPQ and NO) are shown as well. See the Glossary (above) for definitions and the Methods and Materials (below) for further information. See Figures 19 - 24.
How Does Lighting Affect a Museum's Artwork?
In addition, a trial with no light would show the effect of light versus no light in the plant’s production of photosynthesis.
Other variables that we could tweak are concentration of bicarbonate and type of plant.
Comparing experimental results
By: Emily, David, Michael
Quantum Dot LEDs Present Cost Effective Solution to LED Lights
Black light, or UV-A radiation, produced by a fluorescent lamp was used to determine if zooxanthellae can utilize these wavelengths in photosynthesis. About 28% of this lamp's output is in the range visible to the average human eye, according to analysis with a spectrometer. See Figures 5 through 7, & Table 3.
Spectralight I and II Users: Come Out of the Dark and Into the Light!
The following sections describe light bandwidths, the light sources used in the procedures (in great detail), and the photosynthetic responses of a coral's zooxanthellae to these light sources. If this is not of particular interest, skip to the Discussion section.
The Effect of Black Light on Plants | Hunker
Figure 19. Take home message: The green line shows that photosynthesis occurs when the coral's Zooxanthellae is illuminated with black light. This figure shows the of energy dissipation pathways when a black light is used as the light source. Since a PAR meter does not 'see' the maximum output of the lamp at 365nm, no ETRs can be calculated. Note that PPFD detected by the Li-Cor PAR meter during this procedure was less than 1 µmol·m²·sec.