DNA bond strength (nucleotides)
“Crazy Glue”:
Strongest bonds are between Cytosine and Guanine, strong like Crazy Glue (3 H-bonds), whereas the A=T only have 2 H-bonds.
This is relevant to DNA replication, as the weaker A=T will be the site where RNA primer makes the initial break.

Mitochondrial DNA (mt DNA) properties
“mt DNA”.
mt stands for:
Maternal Transfer
Mutates Tremendously (high mutation rate)

tRNA: molecular shape
Fortunately, tRNA (Transfer RNA) is shaped like a capital T.

Pyrimidines are CUT from purines
Pyrimidines are Cytosine, Uracil, Thiamine and are one ring structures.
Purines are double ring structures.