Question

The third assumption in predicting RNA secondary structure is that the structure is assumed to be formed by _____ of the chain back on itself in a manner that ________

(a) crossing, produces knots

(b) crossing, does not produce any knots

(c) folding, produces knots

(d) folding, does not produce any knots

Answer 1

The correct option is (d) folding, does not produce any knots

For explanation I would say: The best way of representing this requirement is to draw the sequence in a circular form. The paired bases are then joined by arcs. If the total structure with all predicted base pairs is to be free of knots, none of the arcs must cross.