What is the boundary between the mesosphere and thermosphere called?

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

This is the nitrogenous base only found in rna

Forensic scientists think they know the identity of a skeleton. what rule should they use to select a relative whose dna could be used to try to confirm the identity?