(Figure 19

question 102

Multiple Choice

(Figure 19.14) In the experiment associated with the figure, acorn barnacles facilitate the growth of algae. If you removed both acorn barnacles and the limpet predators of algae, what would you be likely to observe over time?

• A) a dense carpet of little brown barnacles only
• B) a carpet of little brown barnacles followed by algal growth
• C) no colonization of any organisms
• D) a dense carpet of algae only

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Definitions:

Coelomic Fluid

A fluid found within the coelom, the body cavity of most animals, that serves various functions including circulation and the provision of a hydrostatic skeleton.

Mesoderm

The middle layer of an embryo in multicellular organisms, giving rise to muscles, bones, and the circulatory system among other structures.

Water-Vascular System

A network of hydraulic canals unique to echinoderms, such as starfish, used for locomotion, feeding, and respiration.

Exoskeleton

External skeleton of some invertebrates; hard external parts that muscles attach to and move.