Subject: 7th grade Science
Expectation: The purpose of this activity is to introduce students to the area of microbial organisms in nature. Students are expected to identify the various bacteria based on their collections.
Materials: test tube, journal, pen or pencil, colored pencils, nutrient agar dishes, Inoculating-Loops, glass spreader, glass slides, microscopes.
Information on how to prepare agar petri dishes can be clicked here.
Procedures: Prior to going to the Chino Water Basin in Montclair, California, students will be introduced to the subject of microbial organisms in class.
*Prompt questions will be given on the projector head about what is a microbial organism?
*Can you see one with your eye? Why or why not?
*Where can you find these bacteria organisms?
1. After the students are given time to answer in their journals, they will share their answers to the class. We write down the students information on the blackboard.
2. Students then identify the various types of microbial organisms in their textbook. Prior to collecting sample water, a history of the Chino Water Basin will be introduced to students. The following link provides information about this place.
3. Students will be grouped in pairs where they will collect a sample of water from the pond.
4. Upon coming back, they will pipette 0.5 ml (5 drops from a plastic pipetter) of water onto the agarose dish. Sterilize glass spreader using ethanol flame technique (It is advised that the instructor does this procedure). Students will use the glass spreader to apply the organisms around the petri dish. The agarose dishes will be incubated overnight on the countertop.
5. The next day, students will check for growth of white colonies. Using their journal, they will observe and draw what they see.
6. On the third day, students will use the Inoculating-Loops to pick off the white colonies of bacteria. They will place it on a glass slide and look at the microbacteria through the microscope. Then, they will record and draw what they see in their journals. Students can identify the bacteria using their textbook.
Follow-Up Activity: Students will write about their experiences and what they have learned based on this activity. They will share this with their neighbors and the group to check for understanding.
Conclusion: It is the goal that students will understand that even the smallest microorganisms are important to the survival of the environment and they contain genetic DNA information. Although many bacteria has not been identified, researchers are partaking on an exciting journey to identify and classify these organisms. The Woodrow Wilson Fellowship Program at Lawrenceville, N.J. for teachers allowed us to have a taste of what it's like to be researchers identifying bacteria.
