Q8 of 465 Page 50

What are biofertilizers? In what sense are they better than chemical fertilizers?

Some microorganisms such as nitrogen fixing bacteria, cyanobacteria, fungi and other microflora live and develop near the roots of plant inside soil. They convert nitrogen of the air into nitrogenous compounds (ammonia and nitrate) which serve as plant nutrients. Since these microorganisms enrich the soil with nutrients and improve soil fertility, hence also collectively known as biofertilizers.


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6

Look at Figures 1,2 and 3 given alongside and answer the following questions:


(a) What do these figures show all together?


(b) Which one is queen bee?


(c) Which one of them is the haploid, fertile male?


What it called?


(d) What is the status of the insect shown in the figure: individual? social?

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Each beehive consists of thousands of hexagonal thin-walled fragile cells. Name the material which is used to make these cells and mention the significance of the hexagonal shape of the cell.