A typical human yawn lasts for about six seconds and once initiated, is nearly impossible to stop. Although there are many hypotheses for why we yawn, it is accepted that yawning is contagious - when we see someone else yawn, we often find ourselves yawning as well. This happens across all cultures and even in infants! In this case, the yawn an individual observes is ____________, while their own yawn is ____________.

A. an association, a conditioned response
B. a sign stimulus, a fixed action pattern
C. innate behavior, habituation
D. reflex response, learned behavior


B. a sign stimulus, a fixed action pattern

Biology & Microbiology

You might also like to view...

The use of ________ is the easiest and most effective way of studying many animal and plant viruses

A) bacterial cultures B) tissue or cell culture C) live hosts D) prophages

Biology & Microbiology

The fossil record indicates that the immediate ancestors of modern marine animals diversified in the ____ period, right

after the ____ extinction.

a. Ordovician; Cambrian

b. Jurassic; Triassic c. Carboniferous; Devonian d. Paleogene; Cretaceous e. Triassic; Permian

Biology & Microbiology

Agastino Bassi demonstrated that a type of silkworm disease was caused by a fungus and proposed that many diseases are caused by microorganisms.

Answer the following statement true (T) or false (F)

Biology & Microbiology

Memory cells do not require B cell receptors

Indicate whether the statement is true or false

Biology & Microbiology