*The Wrath of Khan* gives insight into how many different forms of life there actually are in the Star Trek multiverse

"Starship log, stardate 8130.4. Log entry by First Officer Pavel Chekov. Starship Reliant on orbital approach to Ceti Alpha VI in connection with Project Genesis. We are continuing our search for a lifeless planet that will satisfy the requirements of a test site for the Genesis experiments. So far, no success."

Upon first watching the movie and hearing this log entry, I never gave much thought to what Chekov is actually saying. They cannot find a lifeless planet in a universe which is currently (like real life here) believed to be almost completely devoid of life. This puts into perspective just how many different forms of life are in the Star Trek multiverse and what is considered life. We know of artificial life (Data), silicon based life (Horta), even life within gas giants (TNG "Interface"), but what else is "life" according to Starfleet and how much of it is there?

[Edit] I propose that there is just such a massive abundance of life (colonized or natural) in all states of evolution and based upon all sorts of elements (carbon, silicon, etc.) within the Star Trek multiverse that finding a dead planet is an immense challenge. [End edit] This makes sense in the context of the Genesis Project because, as we know, they needed a completely lifeless planet to detonate the device on and build up from nothing. Even a mostly dead planet wouldn't suffice because mostly dead is slightly alive and that would negate the experiment. We also know that there are countless colonized worlds in the known galaxy as well as countless more uninhabited worlds. However, uninhabited does not equate to lifeless since the Federation has colonized uninhabited worlds with plenty of plant and non-sentient life throughout its history. To answer the question of just how many different forms of life there are in the multiverse, I quote Lt. Tuvok when I say "unknown", but the fact that there are next to no dead planets to choose from for the Genesis Project suggest that the number is close to infinite. From a real world perspective, that is not only extraordinary but awe-inspiring since these events are only two short centuries in the future.

[Edit] I have removed the amino acid bit.