Sexual reproduction in Spirogyra is an advanced feature because it shows:
Sexual reproduction in Spirogyra is an advanced feature because it shows:
different sizes of motile sex organs
same size of motile sex organs
morphologically different sex organs
physiologically differentiated sex organs
Solution
In Spirogyra, the sexual reproduction involves the fusion of two morphologically identical isogametes and physiologically dissimilar anisogametes. This is a case of primitive anisogamy.