Which term describes an innate, stereotyped sequence of movements triggered by a specific external stimulus?

Which term describes an innate, stereotyped sequence of movements triggered by a specific external stimulus?

• A. Fixed action patterns
• B. Imprinting
• C. Reflexes
• D. Instincts

Answer: (A)

A fixed action pattern is an innate, species-typical sequence of movements that is reliably triggered by a specific external cue (a sign stimulus). Once started, the sequence tends to unfold to completion in a stereotyped way, regardless of changes in the environment. This precisely captures the idea of an unlearned, hard-wired program driving a predictable set of actions. Imprinting is learned during a critical period, not an inborn fixed sequence. Reflexes are simple, quick motor responses to stimuli and don’t involve extended, ordered sequences. Instincts is a broad label for innate behaviors, but it doesn’t specify the fixed, sequential structure that the term fixed action pattern conveys.

A fixed action pattern is an innate, species-typical sequence of movements that is reliably triggered by a specific external cue (a sign stimulus). Once started, the sequence tends to unfold to completion in a stereotyped way, regardless of changes in the environment. This precisely captures the idea of an unlearned, hard-wired program driving a predictable set of actions.

Imprinting is learned during a critical period, not an inborn fixed sequence. Reflexes are simple, quick motor responses to stimuli and don’t involve extended, ordered sequences. Instincts is a broad label for innate behaviors, but it doesn’t specify the fixed, sequential structure that the term fixed action pattern conveys.