Say you have an organism with a genome of 1 thousand bases 1

Say you have an organism with a genome of 1 thousand bases (10³) and a forward primer made up of 4 nucleotides (aka, a 4-mer).

d. How many possible places can your forward primer match in the genome? This is easy. Focus just on one strand of DNA.

Answer

The organism has a Genome of 1000bp or 1030 bp

Forward Primer is made up of 4 bases

If all the bases (GATC) all in equal proportion within the genome, then primer of 4 b long will be repeated after every 4⁴ base pairs.

Hence, After every (4 x 4 x 4 x 4) 256 bp, primer of 4 bases long may anneal on DNA

If this genome is1000bp, the possible places where primer matches will be 3

If this genome is1030bp, the possible places where primer matches will be 4