The higher invertebrates are divided into two evolutionary lines, protostomes and deuterostomes. this division is based on which developmental feature?
a. wether the blastopore ultimately develops into a mouth or an anus

b. wether the embryonic cells undergo spiral or radial cleavage

c. wether the coelom forms by splitting the mesoderm or through the pocket of the gut.

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

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

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this