Question

19. You notice green scum floating on the surface of a pond. How can you tell whether these organisms are plants? (5 points)

Answer 1

Well the green on the top of the water would have to be collected. I would look at it first for the obvious. Duckweed forms a scum like surface on ponds and that is the smallest flowering plant. If rule that out I would look for tread like green scum which could be an Algae. After that I would get out my microscope and look for Protists and Cyanobacteria. But a microscope is pretty much a necessity when looking at pond scum.

Answer 2

iodine test should be negative if it is a plant

or fermentation test for cellulose would not produce carbon dioxide