One and So-and-so

One noun - A U.S. currency bill representing 100 cents.

So-and-so and one are semantically related In some cases you can use "So-and-so" instead a noun "One".

So-and-so noun - A person whose behavior is offensive to others.

One and so-and-so are semantically related in importance topic. Sometimes you can use "One" instead a noun phrase "So-and-so".