While sampling marine plankton in a lab, a student encounters large numbers of fertilised 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 true coelom. These eggs probably belonged to a(n) ________.
A) echinoderm
B) mollusc
C) nematode
D) arthropod

Question

Quizplus · Accepted Answer

Molluscs are known to develop in this way, with the blastopore developing into the mouth and eventually having a true coelom. Echinoderms develop into a blastula with a blastopore, but their development is different after that point. Nematodes develop without a true coelom. Arthropods have a different type of development with a segmented body plan.

While Sampling Marine Plankton in a Lab, a Student Encounters