2644 - CSUN ScholarWorks - California State University, Northridge

12 · Journal of Student Research Abstracts
2661
COLLEMBOLA IN CAPTIVITY.
B. Arias and M. Mammary (teacher). William Mulholland Middle School, 17120 Vanowen St., Van Nuys,
CA 91406.
The purpose of this study was to determine if more than one family of Collembola could be found in the
same area of the northwest garden at Mulholland Middle School, and to determine how long they can survive
in captivity. My hypothesis was that many families of Collembola can be found at the same site and survive
captivity.
Collections were made from a 20cm. by 20cm. mapped area of the garden. Collembola was collected using
the Tullgren funnel and looping techniques. Cultures were maintained in an activated charcoal and plaster of
Paris base. Cultures were kept at room temperature and fed yeast and water as needed. Onichiuridae family
was identified in one of the cultures, but they died after 24 hours in captivity. lsotomidae family was also identified
but they are still alive after four weeks and they are active and reproducing. Eggs and youngsters can be
identified. I conclude that my hypothesis was correct. Different families of Collembola were identified at the
same site and I have successfully maintained cultures of Isotomidae in captivity.
2262
THE EFFECTS OF UlTRAVIOlET RADIATION ON CHLOROPLASTS IN
EUGLENA AND ELODEA.
Alex Vaynerman and B. Krieger (teacher), Pacoima Middle Schoot, 9919 Laurel Cyn. Blvd, Pacoima, CA
91331.
Objective. Our project's main purpose was to determine the effects on oxygen production when a concentrated
UV source was used to bombard Euglena and Elodea organisms at 24, 48, 96, 192, and 384 hour increments,
thus simulating the earth's futuristic conditions. Since all life on earth depends on the oxygen given off
by. chloroplasts, and since 90% of the earth's oxygen comes from the oceans (which contain Elodea) we
believed that this project would make a very outstanding contribution to our futures.
Materials and Methods: We took use of the Euglena and Elodea and kept a control group of each under
a growing lamp and an experimental group set in a box with a growing lamp and a UV light source of 300nm-
400nm wavelengths. The Elodea was kept close to the surface of the pond water and the Euglena were kept in
petri dishes with a wheat and rice medium. After each session we would count the number of chloroplasts in
each organism by eye through a phase microscope. We originally tried using a spectrophotometer to determine
the amount of oxygen being released by these chloroplasts, but early results proved to be too insignificant to
support any results. Counting chloroplasts provided us with the best idea of the detrimental effects that UV
light would have on organisms.
Results: We found that there were severe reductions in the number of chloroplasts available for the Euglena
and Elodea. The Euglena had a much greater loss in chloroplasts than the Elodea did, causing us to believe
that Euglena might be more susceptible to UV radiation. Thus oxygen production decreased.
Conclusion: Our results backed up our premises on the damaging effects that an ultraviolet ingested earth
would have to face in the coming decades. Our world as a whole will face staggering losses in oxygen as well
as life if the polluted trends continue to wreak havoc on the ozone layer. Our project was able to prove that in
a futuristic condition with more UV light in the atmosphere, which is the way trends are continuing right now,
life will have an immensely difficult time surviving.