John watson and rosalie rayner (1920) conditioned baby albert to fear a white rat by pairing it with a loud noise that albert already feared. after the conditioning had taken place, the researchers also found that albert was afraid of furry white and gray objects, such as a rabbit and a santa claus mask. the fact that albert was afraid of these additional items demonstrated that: a. stimulus generalization had occurred. b. discrimination had occurred. c. extinction had occurred. d. higher-order conditioning had occurred

D. higher-order conditioning had occurred

Explanation:

Higher Order Conditioning is a classic Pavlov conditioning term that refers to a situation in which a previously neutral stimulus is paired with a conditioned stimulus to produce the same conditioned response as the conditioned stimulus.  

In the case of the experiment conducted by John Watson and Rosalie Rayner, baby Albert was subjected to a situation in the presence of a stimulus that was previously neutral (the presence of a white rat that did not generate fear in the baby), paired with a conditioned stimulus ( the loud sound that frightened the baby) so that the baby would associate the sound with the hairy animal's presence and have the same response to both stimuli.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products