Use the drop-down menus to complete each sentence.
is an interaction in which one organism kills and eats another.
is an interaction in which two organisms require the same limited resources.
is an interaction in which organisms work together to improve their survival.

To test the responsiveness of the kidneys, scientists have designed an experiment tracking urine output of people during a normal day, while regulating the in-take of water by mouth. what would be an appropriate hypothesis for this experiment?

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas

Mulitple choice which of the following is a function of the nucleus? a. stores dna b. stores sugars c. builds proteins d. packages proteins