9. What is the base-pair rule for RNA?

The base pair rule for RNA is that adenine pairs with uracil, thymine pairs with adenine and cytosine pairs with guanine.

Explanation: RNA contains adenine, uracil, cytosine and guanine while DNA contains adenine, thymine, cytosine and guanine. Thymine is not found in RNA while uracil is not found in DNA. In RNA base pairing, Watson and Crick proposed a rule that wherever adenine is found in DNA, Uracil occurs in the complementary RNA strand, wherever thymine is found in the DNA strand, adenine is found in the complementary RNA strand and wherever guanine occurs in the DNA strand, cytosine is found in the complementary RNA strand.

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus