While Sampling Marine Plankton in a Lab, a Student Encounters

question 13

Multiple Choice

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 true coelom. These eggs probably belonged to a(n) ________.

• A) echinoderm
• B) mollusc
• C) nematode
• D) arthropod

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Definitions:

Circumferential

Pertaining to or forming a circle or a circumference.

Concentric

A type of muscle contraction where the muscle shortens while generating force, commonly occurring during the lifting phase of an exercise.

Interstitial

Pertaining to spaces within tissues or organs, outside of the blood vessels and cells.

Appositional

Pertaining to growth or deposition of new tissue layers on existing layers, as seen in bones and some tissues.