The sea slug Pteraeolidia ianthina can harbour living dinoflagellates (photosynthetic protists) in its skin. These endosymbiotic dinoflagellates reproduce quickly enough to maintain their populations. Low populations do not affect the sea slugs very much, but high populations ( 5 × 105 cells/mg of sea slug protein) can promote sea slug survival.
Percent of sea slug respiratory carbon demand provided by indwelling dinoflagellates.
-In the graph, the percent of the oxygen demand contributed by the dinoflagellates is greater than 100% during much of the year. What is the fate of this "excess" energy?
A) It is dispersed as "entropy" (disorder in the system).
B) It is saved for producing offspring by the sea slug.
C) It is used to move around the sea bottom.
D) It is used in evaporative cooling by the sea slug.

Question

The sea slug Pteraeolidia ianthina can harbour living dinoflagellates (photosynthetic protists) in its skin. These endosymbiotic dinoflagellates reproduce quickly enough to maintain their populations. Low populations do not affect the sea slugs very much, but high populations (> 5 × 105 cells/mg of sea slug protein) can promote sea slug survival. 
Percent of sea slug respiratory carbon demand provided by indwelling dinoflagellates.
-In the graph, the percent of the oxygen demand contributed by the dinoflagellates is greater than 100% during much of the year. What is the fate of this "excess" energy?
A) It is dispersed as "entropy" (disorder in the system). 
B) It is saved for producing offspring by the sea slug. 
C) It is used to move around the sea bottom. 
D) It is used in evaporative cooling by the sea slug.

Quizplus · Accepted Answer

The excess energy is likely used to produce offspring as suggested by the statement in the passage that high populations of dinoflagellates can promote sea slug survival.

The Sea Slug Pteraeolidia Ianthina Can Harbour Living Dinoflagellates (Photosynthetic