Which of the following is not true regarding the structure of rna?
a. rnas with extended regions of base-pair complementarity adopt a helical form identical to b-type dna.
b. the ribose ring has a hydroxyl (-oh) group on its 2' carbon.
c. bases in rna can form non-watson-crick base pairs.
d. base-pairing between short complementary sequences can fold a single-stranded rna into a stable 3-dimensional structure.
e. rna does not form adenine-thymine (a-t) base pairs.

Option (a).

Explanation:

RNA is present as genetic material in some viruses only. RNA contains the nitrogenous bases ( adenine, thymine, uracil and cytosine), oxyribose sugar and the phosphate group.

RNA has uracil instead of thymine that pairs with adenine. RNA may have the extended base pair region complementarity but they do not have the ability to adopt the helical confirmation similar to the B- DNA.  

Thus, the correct answer is option (a).

. ph changes the ability of them he enzyme to dissolve in water.