write a C. E.R on why nitrogenous bases (A, C, T, and G) that make up the "rungs" of the DNA ladder are so important to life. Please turn that in here. Please use the claim: "Nitrogenous bases and the order they are in is essential to life

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.

Prokaryotic and eukaryotic cells are different in many ways other than the presence or absence of a nucleus. if both archaebacteria and eubacteria are prokaryotic cells, then why are archaebacteria more closely related to eukaryotic cells than they are to eubacteria?

5. what might happen if you were to remove all light from the setup after the discs have all become buoyant? describe what you would see. explain why this would occur with relation to cellular processes like respiration. [referring to an ap biology lab in which spinach discs are placed in a sodium bicarbonate solution and exposed to light.]