According to the article Sound familiar about the ability of newborns to remember speech sounds, the variable which is manipulated or created by the experimenter is the:

The only known molecule that can replicate or reproduce itself is ________

a. messenger RNA b. monoamine oxidase c. RNA d. DNA

Collins and Quillian's model of semantic memory suggests that:

A) semantic memory does not rely in networks of information B) most people really see a penguin to be as much as a bird as a canary C) semantic memory consists of a small network of concepts D) semantic memory consists of a vast network of concepts E) organization of concepts is unnecessary and actually redundant