Question

Assertion :Although, living organism always arise from other living organism, life should certainly have had a beginning. Reason: The study of the conditions and the mechanisms involved in the creation of most primitive living structures on Earth is actually the problem of origin of life.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Life originates from pre-existing life forms and the process is termed as biogenesis. According to Oparin and Haldane’s theory of biochemical origin of life, life originated spontaneously from non-living matter in primitive atmosphere of earth (abiogensis). Assertion is correct.

The primitive reducing atmosphere of Earth was rich in water vapour, carbon monoxide, carbon dioxide, nitrogen and hydrogen. UV light, high temperature and lightening served as sources of energy for chemical reactions between above mentioned gases to form simple organic compounds which in turn produced more complex organic compounds and finally the first living cell. The reducing atmosphere and absence of life on primitive Earth favoured origin of life which is not possible in present day oxidizing atmosphere because the compounds are readily oxidized as soon as they are formed. Thus, now life is not originating spontaneously but only biogenesis exists. Reason is correct.