Discuss how comets might have a role to play in life evolving on an earth-like extrasolar planet in a distant solar system.

can some one please help me out here.

If life came to Earth via a comet, wouldn't it make sense to predict that some comet could carry life to some other celestial body?

Comets also contain a lot of water in the form of ice. Comet impacts could have provided most of the water in Earth's oceans, see here:

http://www.sciencedaily.com/releases/2001/05/010521072649.htm

The answer to this is in the B12 reprints.