TY - BOOK AU - Dijamco, Teresita Derez. AU - ED - ED - ED - ED - TI - : enrichment activities in Ecology SN - 2 PY - 0000///46 CY - PB - KW - KW - 2 KW - 0 KW - 6 KW - 20 N1 - Thesis (M.A.)-- Pamantasan ng Lungsod ng Maynila, 1999.;A thesis presented to the faculty of the Graduate School of Arts, Sciences, Education and Nursing in partial fulfillment of the requirements for the degree Master of Arts in Education, Biological Science; 5 N2 - ABSTRACT: PURPOSE: This study was conducted to biologically assess San Pedro River System for possible contamination and the degree of contamination using Allium Test with macroscopic and microscopic parameters for observation. Specifically, this study attempted to answer the following questions: 1. Will Allium cepa treated with water from the San Pedro River System exhibit cytogenetic changes? 2. Are there significant differences among the following macroscopic parameters: lengths, root number, color, turgescence, and forms of onions grown on different test water samples and the control? 3. Are there significant differences in mitotic indices, microscopic observations of onions grown on different water samples and the control? 4. Could enrichment activities in Ecology be developed from this study that could be used in an Ecology laboratory class in the tertiary level? METHODOLOGY: The test materials used were onions bulbs (Allium cepa variety aggregatum). One hundred forty onion bulbs were used for the experiment. Bulbs of equal sizes were placed on top of test tubes filled with river water samples and control tap water. Each water sample was tested by a series of 20 bulbs. On day 3, seventy onion bulbs from each station were observed using macroscopic parameters. The same seventy onion bulb were harvested afterwards for microscopic analysis. The remaining bulbs were photographed on day 5. FINDINGS: 1. There were significant differences in length of roots (longest and shortest), turgescence of the roots, bent roots of the onions grown on six test water samples from the mean of the control. 2. Among series of onion grown on water samples collected from different sampling sites, the shortest roots, reduced number, discoloration, slightly turgid, and deformed roots (bent and bulbous) were observed in station 3 and 6 that suggested the toxicity of the water in the mentioned sampling sites. 3. The mean of mitotic indices of station 2, 3, 4, 5 and 6 were significantly smaller from mean of the control and station 1. 4. Stickiness, C-mitoses, vagrant chromosomes, and bridges were observed microscopically on some onions grown on the test water samples. 5. The colchicines treated onion root tips showed the chromosome morphology of the cells. 6. Evaluation based on the macroscopic and microscopic parameters suggested stations 3 and 6 to be most polluted sites. 7. Enrichment activities could be developed for Ecology laboratory class in the tertiary level. CONCLUSIONS: In the light of these findings, the following conclusions were drawn: 1. The onions treated with water from the San Pedro River System exhibited cytogenetic changes. 2. There were significant differences in most macroscopic and microscopic parameters between onions grown on test waters and control. The reduced length roots, reduced number, discoloration, slight turgidity, and deformed roots were observed in stations 3 and 6 suggesting the toxicity of the water in the said sampling sites. 3. The mitotic abnormalities observed in the root tip cells suggested the toxicity of the water where the degree of toxicity is higher at stations 3 and 6 and lower degree of toxicity at stations 2, 4, and 5. A correlation has been demonstrated between reduced root growth and lowered mitotic activities in the cell of the onion root tips. With increased toxicity of the water, there was increased mitotic disturbances translated to low mitotic index and reduced growth of roots and vice versa. The Allium Test revealed that the status of the San Pedro River System is water fit for the propagation of growth of fish and other aquatic resources for the upper reach of the river (class C) and water that could be used for agricultural purposes and irrigation for the downstream portion of the river up to the entry point of Laguna de Bay (class D). 4. Simplified enrichment activities in Ecology laboratory class in the tertiary level were developed. These activities when used by students hope to create or increase awareness on environmental problems existing today and affecting not only them but other members of the society. As such, these enrichment activities may serve as a tool for the students to contribute to the solution of environmental problems like pollution of river systems. RECOMMENDATIONS: In view of the observation gathered from this study, the following recommendations are forwarded: 1. Use of other test systems or other biological indicators such as animals or plants from onions to determine if the assessment on the San Pedro River System will yield the same as in Allium Test. 2. Chemical analysis of test water samples should be done to complement the results gathered from the study. the suggested toxicity of the water samples especially from stations 3 and 6 should be reinforced by the identification of substances causing the toxicity of the water. 3. A study should be conducted using water samples collected on a dry season for comparison to the results of this study where water collection was done in October, a rainy season month. 4. Periodic assessment of the San Pedro River System using Allium Tets. 5. Evaluation of the validity of the enrichment activities when used by students on environmental problems and ways of solving them. 6. Use of the environmental activities in Biology laboratory class to create or increase environmental awareness among Biology students ER -