Identify A and B illustrations in the following

Identify A and B illustrations in the following :

a. (A) - AATTc / Sticky end
(B) Ori / Origin of Replication
b. Pallindromic sequence, because the sequence of base pairs reads same on the two strands when orientation of reading is kept the same.
c.PCR - Polymerase Chain Reaction
Importance - amplification of gene of interest