Most body systems maintain homeostasis through a) cyclic feedback b) neutral feedback c) positive feedback d) negative feedback

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.

This is the nitrogenous base only found in rna

According to these anatomical structures which two animals are probably most closely related