To observe filamentous algae under microscope.
Apparatus : Microscope, slide, coverslip.
Materials : Glycerine, pond water, blotting paper.
Procedure :
`rarr` Collect water from a lake or pond that appears dark green and contains filamentous structure.
`rarr` Put one or two filaments on a slide.
Put a drop of glycerine on the filaments and cover it with a coverslip.
`rarr` Observe the slide under a microscope.

How do spirogyra reproduce asexually ?

Explanation

Spirogyra reproduces asexually by fragmentation.