Simran Vinaik
Last Activity: 6 Years ago
Zygospore are thick walled sexual spore. It is a diploid spore and is a resting spore and resistant to unfavorable environmental condition. Under suitable condition zygospore germinate. Before germination, diploid nucleus of zygote divide meiotically into haploid nucleus. Three of which degenerate and only one become functional.
During germination outer wall of spore absorb water swells up and burst exposing inner layer as cylindrical germ tube. The germ tube divides to form two celled structure. Lower cell form rhizoids and attached to substratum while upper cell divides repeatedly to form new filament. The filament get detached from the substratum and become free floating Spirogyra.