Alex listed the typical steps of fossil formation. 1) an organism dies. 2) the remains fall to the bottom of the ocean. 3) the soft portions decay, and the hard portions remain. 4) the sediment becomes rock. which statement describes the missing step?

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim