Organisms that eat other organisms are called .

This rapid change in species that rarely leaves behind fossil evidence is referred to as

American scientist, linus pauling, was one of many scientists racing to discover the molecular structure of dna. pauling initially thought that the molecule was a triple helix. later, james watson and francis crick unveiled their double helix model, which turned out to be an accurate description of the molecule's shape. why did watson and crick succeed when pauling failed?

All of these things can block a bronchus and cause collapse of a lung except