AP BIOLOGY

Detailed explanation-1: -The specific type of stimulus which triggers a fixed action pattern is often called a sign stimulus, key stimulus, or a releaser. The sign stimulus triggers a complex neural pathway called an innate releasing mechanism, which begins a behavioral cascade.

Detailed explanation-2: -A Fixed Action Pattern, often abbreviated as FAP and known alternatively as Instinctive Movement or Instinct Bewegung, is a predictable series and stereotypical sequences of complex actions triggered by a cue.

Detailed explanation-3: -Fixed Action Pattern (FAP) is a sequence of coordinated movements that are performed together as a “unit” without interruption. Each FAP is triggered by a unique stimulus variously known as a sign stimulus, a key stimulus, or a releaser. A praying mantis striking at prey is a typical example.

Detailed explanation-4: -sign stimulus (releaser) The essential feature of a stimulus, which is necessary to elicit a response. For example, a red belly (characteristic of courting male sticklebacks) is the sign stimulus necessary to provoke an attack from a rival male; even a very crude model fish is attacked if it has a red undersurface.

Detailed explanation-5: -Part of a stimulus that is sufficient to evoke a behavioural response in an animal (e.g. the patch of red colour that provokes an aggressive reaction in Erithacus rubecula, the European robin). From: sign stimulus in A Dictionary of Zoology »