While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. The student rears some of the eggs in the laboratory for further study and finds that the blastopore becomes the mouth. The embryo develops into a trochophore larva and eventually has a coelom and a hemocoel. To which group of organisms did these eggs likely belong?
A) echinoderms
B) molluscs
C) nematodes
D) arthropods

Question

Quizplus · Accepted Answer

The development of a trochophore larva and the presence of a coelom and a hemocoel are characteristic of molluscs. Additionally, in molluscs, the blastopore develops into the mouth, which is a feature of protostomes, including molluscs.

While Sampling Marine Plankton in a Lab, a Student Encounters