Q1 of 32 Page 8

What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?

• Cyanobacteria are capable of fixing nitrogen with the help of specialised cells called the heterocyst.


• They enrich the soil fertility. Hence BGA’s are used in agricultural fields. E.g. Colonies of Nostoc and Anabena grows in Paddy field.


More from this chapter

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11

Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to?

 12

Members of phycomycetes are found in

i. Aquatic habitats


ii. On decaying wood


iii. Moist and damp places


iv. As obligate parasites on plants Choose from the following


options


 2

Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it, you place the slide under microscope and observe the following features :-

a. Unicellular


b. Well defined nucleus


c. Biflagellate–one flagellum lying longitudinally and the other transversely.


What would you identify it as? Can you name the kingdom it belongs to?


 3

How is the five–kingdom classification advantageous over the two kingdom classification?