What ecosystem factors decreases in responses to human activities that cause the ecosystem to be fragile?

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.

With regard to enzymes, key is to lock as a) substrate is to activation energy eliminate b) product is to substrate. c) enzyme is to active site. d) substrate is to active site.

Up to what percentage of the world's flora consisted of cycads during the triassic period? 100% 75% 50% 20%