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December 3, 2015


Highlighting 8th Grade Science

Eighth grade scientists are observing planaria during their studies of asexual reproductions, as part of their unit on heredity. Planaria are tiny flatworms that live in freshwater and marine environments. A single planaria can be cut into multiple pieces, and each piece will grow back into a whole planarian. Planarians can use this ability to reproduce asexually, and in essence, clone themselves.

Students have had the opportunity to read about multiple types of asexual reproduction (fission, budding, fragmentation, parthenogenesis), and last week they examined the pros and cons of an organism inheriting genetic material from only one parent.

Using a dissecting microscope, students worked in small groups to measure and record the length of their planaria, and then they used a scalpel to cut it into two pieces. Once the planria was cut, they measured and recorded the length of both the tail section and the head section. Students input their personal data into a spreadsheet that’s shared by the entire eighth grade class.

Throughout the next several weeks, each group will be taking additional measurements and adding them to the spreadsheet. Data will be analyzed to determine the percent of successful head and tail survival, and the percent of successful regeneration.

For more information, contact MRH School District at (314) 644-4400.