Which of the following statements about pcr is/are false? there may be more than one correct answer.

a) pcr reactions contain dna template, primers, deoxyribonucleotide triphosphates, and heat- resistant dna polymerase
b) each pcr cycle includes three steps: denaturation, annealing, and extension
c) after each pcr cycle, the amount of dna increases in a linear manner
d) one limitation of pcr is that it requires prior knowledge of the sequence to be amplified
e) pcr is a very sensitive technique and can amplify target sequences present in extremely low copy number
f) the single-stranded dna primers must anneal to opposite strands of template dna at distant sites, with their 5′ ends directed toward each other