What is the density of a cube that has a volume of 3 cm3 and a mass of 12 g?

What type of appendages do sponges cnidarians roundworms annelids mollusks arthropods echinoderms and vertebrate have? jointed, not jointed, absent  

_tissues respond quickly to outside stimuli a) epithelia b)nervous c)muscular d)muscular and nervous

Recombinant dna is the merging of dna from unrelated organisms to create new genetic varieties is assembled in the lab from mononucleotides was part of the green revolution of the 1960s is pollination of one plant by another of the same species is cross-pollination of one plant by a different species