Page 1 - 3- Home assignment II (Worksheet)- Biogeochemical cycles-2
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SAI International School
                                                 Subject- Biology
                                          Chapter- Natural Resources
                                    Subtopic- Bio- geo chemical cycles-2
                                                     Module- 34
                                               Home Assignment II

                                                    WORKSHEET-2
                 Q1.  Ozone is found in the
                        (a) stratosphere
                        (b) ionosphere
                        (c) troposphere
                        (d) mesosphere
                 Q2.  One of the following is not the consequence of ozone layer depletion.
                        (a) Malignant melanoma – skin cancer type
                        (b) Increased ultraviolet radiations
                        (c) Tides
                        (d) Cyanobacteria are sensitive to UV rays and would be affected by its
                           increase
                 Q3.  Carbon is found abundantly  in
                        (a) plants
                        (b) soil
                        (c) Fossil fuel
                        (d) Marine organisms
                        DIRECTION : Question nos. 4 and 5 below consist of two statements -
                        Assertion (A) and Reason (R). Answer these questions selecting the
                        appropriate option given below:
                        a)  Both A and R are true and R is the correct explanation of A.
                        b)  Both A and R are true but R is not the correct explanation of A.
                        c)  A is true but R is false.
                        d)  A is false but R is true.
                        e)  Both Assertion and Reason are false.
                 Q4.  Assertion: Biogeochemical cycles are important for the nutrients to go back to
                        the soil.
                        Reason:  These  cycles  involves  conversion  of  complex  substances  to  the
                        simple form.
                 Q5.  Assertion: Greenhouse effect leads to global warming.
                        Reason:  Greenhouse  effect  causes  increase  in  the  atmospheric
                        temperature.
                 Q6.  (a) What are the two sources of carbon on earth?
                        (b) What is global warming?
                 Q7.  (a) Which compounds are released from refrigerators and AC?
                        (b) How does these compounds affect ozone layer?
                        (c) what do you mean by ozone layer depletion?
                 Q8.  Why is nitrogen important for life? Name two bacteria’s involved in  nitrogen
                        fixation.
                 Q9.  Name all the steps involved in water cycle. Explain what would happen if water
                        cycle gets disrupted?
                 Q10.  Draw and explain “Greenhouse effect” on earth.
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