Central Board of Secondary Education
Class – XII (Year 2009)
Subject – Biology - (Delhi)
All Questions are compulsory.
Wherever necessary, the diagrams drawn should be neat and
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.