Which of the following describes a difference between cnidariansand ctenophores?
a. Cnidarians have choanocytes, whereas ctenophores havecnidocytes
b.Ctenophores swim through the water mouth-first, whereascnidarians medusae's power stroke propels them aboral-sidefirst
c. Ctenophores have an acellular layer between an external andinternal layer of cells, whereas cnidarians' external and internallayer of cells touch each other directly
d. Cnidarian tentacles can retract, whereas ctenophore tentaclescannot
true or false: The symbiosis between corals and zooxanthellae isunusual, because the coral can survive forever if the zooxanthellaeleave the coral.
