*All statements are given taking in consideration that single shown strand is a template strand of DNA.
Forward primer attaches to the Start end of the fragment and Revers to the End end of the DNA sequence.

Primers are stretches of nucleic acids (either DNA or RNA) that help in DNA replication. DNA polymerases bind with the primer to add nitrogenous bases to the growing strand. DNA replication in eukaryotes assembles a RNA primer, while in-vitro laboratory methods and techniques like polymerase chain reaction (PCR) use DNA primers.

Forward and Reverse primers are used in the process of polymerase chain reaction. They bind to the DNA strand and direct them toward elongation and amplification.

Forward Primer
Forward Primer is a DNA stretch that attaches to the antisense strand (-) of the DNA that runs in 3’ to 5’ direction. The primers anneal to the DNA strand and bring about amplification. The forward primer is complementary to the strand they bind to. The antisense strand usually serves the strand for synthesis of mRNA, therefore they are called coding strands.

Reverse Primer
Reverse Primers are DNA stretches that bind to the sense strand (+) of the DNA that runs in the 5’ to 3’ direction. They amplify the strand they bind to.

Problem:


A DNA with the sequence:
5'CGCATCGATCATGCCCTGA.....AGTCCCATTAGATGCC3'
needs to be PCR amplified. The reverse primer will have the following sequence:

A) 5'GGCATCTA3' *
B) 5'TAGATGCC3'
C) 5'GGACTCTA3'
D) 5'CGCATCGA3'

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