Investigators are studying a protein that must be phosphorylated to be activated. Which method could be used to separate the phosphorylated form of the protein from the form that lacks an activating phosphate group?

A. differential centrifugation

B. equilibrium sedimentation

C. velocity sedimentation

D. ion-exchange chromatography

E. gel-filtration chromatography

Which is an example of a decomposer? a. bear b.algae c.grass d.bacteria d bacteria

Stephen is a student who wants to test his knowledge of medical terminology. which option could he use?

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.