Which force moves food through the esophagus into the stomach?

In what for do plants utilize nitrogen? why do they need nitrogen?

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.

Aprimary producer stores 9,000 kcal. in the energy pyramid, if a primary producer is consumed by a first-level consumer, and that first-level consumer is consumed by a second-level consumer and the second-level consumer is consumed by a third-level consumer, how much energy is stored by the third-level consumer from the primary producer? *