A stalked, sessile marine organism has several feathery feeding structures surrounding an opening through which food enters. The organism could potentially be a cnidarian, a lophophorate, a tube-dwelling worm, a crustacean, or an echinoderm. Which of the following traits, if found in this organism, would allow the greatest certainty of identification?
A) the presence of what seems to be radial symmetry
B) a hard covering made partly of calcium carbonate
C) a digestive system with mouth and anus separate from each other
D) a water vascular system
E) a nervous system
Hummingbirds feeding on nectar transfer pollen from flower to flower.
The Human Eye and its Structures
The three major structures of the medial temporal lobe, illustrated in the monkey brain: the ...
Basic structures of HIV.
Marine Life Zones "الحياة في أعماق البحار"