Enzymes act as catalysts in biochemical reactions. In the diagram, which represents a catalyst?
A) W
B) X
C) Y
D) WX

Legumes, a type of plant, require rhizobia, a type of soil bacteria, to survive since these organisms fix nitrogen during photosynthesis. rhizobia use the legumes for food. what would most likely happen to the legume population if rhizobia suddenly became extinct?

Awave has a wavelength of 15 mm and a frequency of 6 hertz. what is its speed?

2. cheryl hears a new song on the radio every day during the week on her commute to work. surprisingly, when the song comes on at a party on saturday night, she knows most of the words without trying. describe the three ways that we use cognition to learn without reinforcement. which type of cognitive learning without reinforcement best explains how cheryl knew the song lyrics? explain your answer.