Biology Past Questions and Answers

The function of lenticels is

The following events take place during conjugation in spirogyra 1. The protoplasm of each of the conjugating cell separate from the cell wall to form a Gamete; the gamete of one filament passes through the conjugation tube to meet the gamete of the other filament 2. The zygote soon become surrounded by thick brown wall to become zygospore which burst after a short rest and germinate to produce a new filament 3. The nuclei of the gametes fuse to form a zygote 4. The protuberance meet and where they touch the cell-wall disappear so that a conjugation tube joining the two cell is formed 5. protuberance appear on the wall of the cell of two filament of spirogyra lying side by side opposite one another. Now what is the correct sequence in which the above sequence occur?

Which of the following is a characteristic of animal cell?

Nitrifying bacteria keep the soil fertile by

In the life history of schistosoma (Bilharzia), one of the following is intermediate host