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.

The answer is A whether the blastopore ultimately develops into a mouth or anus

i know because i just took a test and passed with this same question

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.