Stickleback Fish Exhibit Variation in a Morphological Trait Known as Gill

question 67

Multiple Choice

Stickleback fish exhibit variation in a morphological trait known as gill rakers. Fish with long gill rakers are very good at eating plankton, and fish with short gill rakers are good at eating deep-water invertebrates. However, fish with intermediate-length gill rakers are poor at eating either type of food. Fish that are better at consuming food have higher survival and reproduction rates than poorer consumers. Based on this information, what type of selection is likely acting on stickleback gill raker length?

• A) no natural selection
• B) stabilizing selection
• C) disruptive selection
• D) directional selection

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Definitions:

Mimicking a Stroke

The act of a medical condition or another cause imitating the symptoms of a stroke, which is a serious condition caused by the interruption of blood supply to the brain.

States of Consciousness

Different levels of awareness of one's environment and internal states, ranging from full alertness to deep sleep.

EEG

an abbreviation for electroencephalogram, a test that measures and records the electrical activity of the brain using small, flat metal discs attached to the scalp.

Specific Event

A particular occurrence or instance that is distinct and can be identified in time and place.