Thursday, September 29, 2016

HSEB notes | Scalariform conjugation in Spirogyra






Scalariform conjugation is the most common type of sexual reproduction in spirogyra. It takes place in cell of two different filament i.e takes places between heterothallus and dioecious species like S.tuwensis , S. Cylindrica etc.

In this process , two filament of opposite strain come together and lie side by side parallel to each other. They are glued together by mucilage. The cell of each filament develop a short lateral outgrowth called protuberance or papilae. The papilae then start to grown in size and attach through their anterior region. The common wall between the papilae is dissolved by the enzyme cytase and common tube like passage is formed known as conjugation tube. The cell of one filament function as male gametangium and another filament function as female gametangium. After the formation of conjugation tube their protoplast directly function as gamete. Slowly the protoplast of male gamete move towatd female gamete through the conjugation tube. The protoplast of gamete fuse to form zygote. The zygote then secretes a wall around itself and now it is called gametangium.

For more go to original site: http://ohonotes.com/scalariform-conjugation-in-spirogyra-botany-notes.html

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