In your body, the outside "tube" that surrounds a cavity and inner "tube" is derived from the see section 30.2 ( page 616) .

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