Adependent variable is ? a. directly changed by the experimenter ,b. manipulated by changes to the independent variable.,c. a variable that is kept constant.,d. a variable that is used as a control.

An easy way to calculate the amount of energy available at each level is to what?

Which best compares habitat and niche? o niche is a place in which organisms live, and habitat is the way in which an organism fits into its habitat.o habitat is a place in which organisms live, and niche is the way in which an organism fits into its habitat.habitat is a group of organisms that live in an area, and niche is a specific species that lives in that areao niche is a group of organisms that live in an area, and habitat is a specific species that lives in that area.

Match the functions to the cell types ? contraction and relaxation. conducting electrochemical signals fighting diseases carrying genetic material