PLEASE HELP Plant stems grow up from the ground. This is an example of

positive thigmotropism

positive hydrotropism

negative gravitropism

negative phototropism

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