The Nontaxonomic Term Sea Slug Encompasses a Wide Variety of Marine

question 17

Multiple Choice

The nontaxonomic term sea slug encompasses a wide variety of marine gastropods. One feature they share as adults is the lack of a shell. One might think, therefore, that they represent defenceless morsels for predators. In fact, sea slugs have multiple defences. Some sea slugs prey on sponges and concentrate sponge toxins in their tissues. Others feed on cnidarians, digesting everything except the nematocysts, which they then transfer to their own skins. Whereas the most brightly coloured sea slugs are often highly toxic, others are nontoxic and mimic the colouration of the toxic species. Their colours are mostly derived from pigments in their prey. There are also sea slugs that use their colouration to blend into their environments.
This nudibranch, a type of sea slug, has many reddish cerata on its dorsal surface, as well as two white-tipped rhinophores located on the head.
-The nematocysts most likely reach the skin of sea slugs through branches of the ________.

• A) intestine
• B) excurrent siphon
• C) nephridium
• D) pseudocoelom

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Definitions:

Variation

The extent to which data points in a statistical distribution or dataset diverge from the average or mean.

Degrees of Freedom

The number of independent values or quantities that can freely vary in an analysis without violating any given constraints.

Factorial Experiment

An experimental design technique in which the effects of two or more variables are studied at once by changing them together, rather than one at a time.

Interaction

A situation in statistical analyses where the effect of one variable on an outcome depends on the level of another variable.