Why was reverse transcription useful for producing artificial insulin?

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

The term facultative anaerobe refers to an organism that

The backbone of the double helix has an alternating molecules. what do you call these alternating molecule?