While Sampling Marine Plankton in a Lab, a Student Encounters

question 20

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 coelom and a hemocoel. To which group of organisms did these eggs likely belong?

• A) echinoderms
• B) molluscs
• C) nematodes
• D) arthropods

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Definitions:

Demand Curve

A visual display illustrating how the quantity demanded of a product varies with changes in its price, typically sloping downward from left to right.

Short Run

A period of time in economics during which at least one input, such as plant size or capital, remains fixed while others may vary.

Long Run

A period during which all factors of production and costs are variable, allowing for full adjustment to changes.

Perfect Competition

Perfect competition is a market structure where many firms offer a homogeneous product or service, and no single firm can influence the market price.