SAT Subject Biology Practice Question 292: Answer and Explanation
2. An organism appears to be a segmented worm. Upon observation it is determined that the organism has a closed circulation, a mouth and an anus, and does NOT have an exoskeleton. The organism most likely belongs to the phylum
Correct Answer: B
B The characteristics described are those of the phylum annelida, the best example of which is the earthworm. Mollusks have external shells (snails), echinoderms and arthropods have exoskeletons (sea stars, crustaceans, insects), and chordates have endoskeletons and, in any case, are not worms.