2. Some basics…. Many people call this “pond scum” Filamentous green alga (unbranched & varies in length) Phylum Chlorophyta Jelly-like covering surrounds & protects filaments from injury Each cell contains 1-2 ribbon-like chloroplasts (spiral in shape) Small dark bodies called pyrenoids found on chloroplasts (store starch) Sexual reproduction via conjugation (fusion or union of 2 gametes)

4. pyrenoid cell wall sheath cytoplasm chloroplast nucleus

5. Can you pick out any of the structures from the last slide?

7. 1 2 3 4 Single filament 2 filaments align & conjugation tubes form Zygotes form Migrating protoplast Conjugation in Spirogyra can be found on pg. 354 of your text!

8. pyrenoids chloroplasts conjugation tubes

9. Passive cell Active cell Direction of Movement

10. Zygospore The cell walls of the original filaments decay & release the zygospores. After a period of rest, & when favorable conditions return, this zygospore will give rise to a new filament.

11. Talk about…..Spirogyra