SAMPLE PAPER-1 BIOLOGY CLASS X

1.Plants ------>insects ------> frog ------> crow. How much energy will be available if plants absorb 1500 KJ of energy.
2.Name the enzyme that acts on acidic medium and name the organ from which it is released.
3.The wall of arteries thick and elastic, why?
4.Why is variation beneficial to the species but necessary for the individual?
5.Draw neat label diagram of heart showing the direction of blood flow.
6.Why do asexually reproducing organism show very little variation? Do the survival of variants have equal chances?
7.In water harvesting system why is it preferred to store water underground? Give three reasons.
8.(1) Which layer of atmosphere acts as protective layer for living being from harmful rays of sun? How is that layer formed?
(2) Expand UNEP. What is its role in protecting the important layer of atmosphere?