Question

The parallel lines shown here represent the paired strands of a dna double helix. if this molecule undergoes one round of replication, which ends are shorter in the daughter molecules than in the parental molecules?

Answer 1

Based on the image, the y and z line shows shorter ends of daughter molecules. When a molecule of a paired strands of DNA double helix undergoes one round of replication, both 3' ends are shorter in the daughter molecules than in the parental molecules. Both strands of parental DNA serve as templates for newly synthesized daughter strands that inherits a new double helix DNA containing one old and one new daughter strands arising from the parental duplex. This mechanism would require one daughter strand to polymerize in the 5′-to-3′ direction and the other in the 3′-to-5′ direction through the action of DNA ligase.

 

Answer 2

The diagram and the options given for the question above is given below:

Select one:

A. W and X
B. W and Y
C.W and Z
D.Y and X
E. Y and Z
                       W                             X
                3'------------------------------------- 5'

                5'--------------------------------------3'
                       Y                              Z

ANSWER
The correct option is C.
If the molecule undergoes one round of replication, the the TWO THREE PRIME ENDS in the daughter molecule will be shorter than those in the parental molecule. 
DNA replication always results in the production of two daughter DNA molecules. During replication, each strand in a DNA molecule serves as a template for the synthesis of a new complementary strand. Each strand has two ends, the five prime and the three prime ends, these ends give direction to the DNA strands. During replication, the DNA polymerase enzyme add nucleotide to the three prime end of the DNA molecule, thus moving in that direction.