Biology L

         1. Assertion (A) red blood cells burst when placed in water.

           Reason (R) Due to the phenomenon of osmosis, water enters into red blood cells.

        2.  Assertion (A) Reproduction is the process by which living organisms produce young ones of their species. There are different forms of reproduction.

         Reason (R) sex organs, male and female, are mandatory for reproduction.

         3.  Assertion (A) Amoeba reproduces by fission.

            Reason (R) all unicellular organisms reproduce by sexual methods.

       4.  Assertion (A) human being has 23 pair of chromosomes, one of which is the sex chromosome and the remaining 22 autosomes. The X-linked diseases are related to mutations on a sex chromosome.

               Reason (R) colour blindness results from a mutation in X- chromosome.

        5.  Which one among the following is responsible of the expansion of water in the ocean?

(a)    Carbon dioxide

(b)   Nitrogen dioxide

(c)    Carbon monoxide

(d)   Sulphur dioxide

         6. On the packet of a packaged food product, what is the symbol that indicates that the food is vegetarian?

(a)    A green plus mark

(b)   A Green square in a circle

(c)    A green leaf of a plant

(d)   A green circular dot in a square

          7. Genetically modified varieties or hybrids of which of the following are now being widely cultivated in the world?

(a)    Wheat, coconut and mango

(b)   Maize, soyabean and cotton

(c)    Gram, brinjal and orange

(d)   Olive , mustard and groundnut

         8. The purpose of genetically modifying brinjal and cotton as Bt-brinjal and Bt- cotton was to make them

(a)    Drought-resistant

(b)   High-yielding

(c)    Pest-resistant

(d)   Short-duration crops

           9. if the drinking water supply pipeline is damaged and is contaminated with domestic sewerage, whichone of the following diseases in most likely to occur after drinking such water?

(a)    Measles

(b)   Typhoid

(c)    Tuberculosis

(d)   Diphtheria

            10.  Food cans are coated with tin but not with zinc because

(a)    zinc is costlier than tin

(b)   zinc has a higher melting point than tin

(c)    zinc is more reactive than tin

(d)   tin is more reactive than zinc

        Answer:

1.       C

2.       C

3.       C

4.       B

5.       B

6.       D

7.       B

8.       C

9.       B

10.   B