Explain How Agar Helps To Detect The Growth Of Bacteria

700 Words3 Pages
September17.2013 P.4 Environmental Sources Of Bacteria Purpose: We did this lab to find out exactly which conditions would help to grow a bacterium the best. Materials: • Agar • Petri dish • Cotton • Incubator • Tape • Bacteria Procedure: 1. Mark bottom of Petri dish 2. Split petri dish into 4 sections and label the sections 3. Pour hot agar into dish 4. Keep lid off and let agar steam 5. Put top back on and let plate cool 6. Collect piece of bacteria by dabbing it with moistened cotton 7. Dab contaminated cotton onto section of the dish 8. Record source on lab paper 9. Find new bacteria for each sample 10.…show more content…
1. Underneath desk 2. Sink handle 3. School bench 4. Control group Results: |Objects |# Of colonies |% Coverage | |Desk |2 |2% | |School Bench |7 |20% | |Sink Handle |5 |3% | |Control Group |2 |2% | Analysis Questions: 1. Agar helps to detect the growth of bacteria and mold. 2. The main conditions for bacterial growth is good temperature, food, moisture, and time. 3. The surface of the sink handle had the most bacteria growth on…show more content…
The environment for the sources of the bacteria meets the necessary conditions. For example the bacteria on the water fountain was moist and the right temperature, so as a result the bacteria began to grow. 5. We were not able to see any bacteria on the surface of the object without already swabbing it. The bacteria was not visible because, the environment was somewhat not ideal for the bacteria. It could have been the temperature or light. 6. Other mold and bacteria could be found in many places. Here are some other places students in my class found mold and bacteria, the out door bench top, the girls toilet handle, bottom of a shoe, track surface, control group, spout of drinking fountain, and bathroom stall door latch. 7. Bacteria and mold are not always on objects, because the environment is not perfectly ideal for the germ to grow. 8. We know that the mold came from the object we tested because of our control group. 9. Contamination could have occurred in our plates. The air could have had some bacteria in it that came in our plate, the agar could have caught some bacteria through the air when it was cooling, or the cotton swab could have already had some bacteria on
Open Document