Central Board of Secondary Education
Class – XII (Year 2009)
Subject – Biology - (Delhi)
General Instructions:
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All Questions are compulsory.
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Wherever necessary, the diagrams drawn should be neat and properly labelled.
Q.1 Why hnRNA is required to undergo splicing ?
Q.2 How does colostrum provide initial protection against diseases to new born infants ?
Q.3 Name the group of organisms and the substrate they act on to produce biogas.