The major candidate for the factor that forms the Nieuwkoop center was β-catenin (This multifunctional protein also proved to be a key player in the formation of the dorsal amphibian tissues)

TLS Online TPP Program

#Id: 9388

#Unit 11. Evolution and Behavior

Sign stimulus (releaser)

The essential feature of a stimulus, which is necessary to elicit a response.

TLS Online TPP Program

#Id: 9389

#Unit 11. Evolution and Behavior

Male stickleback fish develop red colour on their ventral side in the breeding season and maintain territories. 

When a conspecific male intruder enters their territory, resident males perform an aggressive display. 

The ethologist Niko Tinbergen presented models of different shapes to territorial male stickleback fish. He found that models of any shape elicited aggressive displays, provided the ventral part of the models was coloured red.

TLS Online TPP Program

#Id: 9390

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9391

#Unit 11. Evolution and Behavior

Supernormal’ stimuli - A stimulus that produces a more vigorous response than the normal stimulus eliciting that particular response.

TLS Online TPP Program

#Id: 9392

#Unit 11. Evolution and Behavior

Web making in spiders

Spiders make silk in a special part of their body called a gland and use their legs to pull it out of their bodies. This is called spinning.

TLS Online TPP Program

#Id: 9393

#Unit 11. Evolution and Behavior

Hygienic behaviour in honeybee (Inherited)

uu ‐ Uncapping  

rr‐ Cleaning