Question

Which of the following stretches of RNA is most likely to form a hairpin with 4 bases making up the turn?

Group of answer choices
a. G C U C U A A G G A G C
b. U U G C G C A U A A C G
c. G C U A U U C C G C U A
d. C A C G A U U C G C A C

Answer 1

Option b, U U G C G C A U A A C G, is the RNA strand that can form a hairpin with a 4-base turn due to complementarity and an internal sequence conducive to a hairpin loop.

Step-by-step explanation:

The RNA strand most likely to form a hairpin with a 4-base turn is b. U U G C G C A U A A C G. This is because the hairpin structure in RNA is formed when the molecule folds back on itself and establishes intramolecular hydrogen bonds between complementary bases. In RNA, the four bases are adenine (A), guanine (G), cytosine (C), and uracil (U). A hairpin turn typically occurs when there is a sequence of unpaired bases flanked by regions that can form complementary base pairs.

For a hairpin with a 4-base turn, we look for a sequence where four nucleotides do not participate in base pairing surrounded by sequences that can form hydrogen bonds. In option (b), the sequence UUGC can pair with the complementary GC sequences on the same strand, leaving the four bases AUAA at the turn, which are less likely to form stable hydrogen bonds with each other.