I’m a geneticist by profession, but too often, I realize that I don’t know some of the basic facts. How many RNA molecules are there in a typical mammalian cell? I don’t even know the order of magnitude.
The Bionumbers database is great for looking up this sort of thing. It took me 10 seconds to find the answer: There are 300,000 mRNA molecules in a human cell.
Examples of the hundreds of other numbers you can look up:
Nehaveigur 