The part of earth that contains the air we breathe ?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

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

Where in the cell are ribosomes made?