Question

Where might DNA be found on an envelope?

1) Inside the envelope
2) On the return address
3) On the licked area
4) At the top of the envelope

Answer 1

On the licked area for sure cause you're literally and purposefully dragging a your tongue over it, which can of course have some sort of DNA

Answer 2

DNA can be found on the licked area.

When you lick the envelope to seal it, the dna from your saliva transfers onto the envelope.