It is how DNA works in the case of PCR, for example. The denaturation cycle splits double stranded DNA into individual single strands, which can be thousands of base pairs long. Primers are short sequences that bind to these single strands. If there are only one or two mismatches, the primer can easily bind to the wrong part of the DNA strand, if the temperature during the annealing step is low enough. This causes messy gels and incorrect DNA products in the PCR.

In some cases, if the temperature is very low, the primer can bind to sequences with many mismatches. This results in the scientist crying and finding god.

Yes, I mentioned that in the last sentence of my comment. She said in the video that her blood pressure dropping to a lethal level is very possible due to pre-existing issues.

It says right in the video in the article that she uses contraception and would have an abortion if it failed. I’m sure she would’ve taken a pregnancy test, but that doctor wasn’t having it. What more do you need to feel like this woman should be “allowed” to receive life-saving medication? She was literally passing out from pain. Then was prescribed a med that dangerously drops her already low blood pressure.