What is one possible explanation for the increased amount of carbon dioxide in the atmosphere?

This is a substance, like an enzyme, which speeds up chemical reactions, but does not react itself.

What were early classification schemes based on? A. dissection B. observation C. hypothesis D. behavior

What are two roles prokaryotes play in the cycling of elements in an ecosystem

You have just discovered a new organism that you think is an animal. Which of the following characteristics disqualifies the organism as being an animal? a) possessing cells that have cell walls b) multicellular c) heterotrophic d) eukaryotic

Which two suggestions describe how humans could reduce their greenhouse gass emissions

What is a basic difference in the organization of vascular tissue in eudicots when you compare root and shoot tissues?

How are ecosystems named? by the climate it is associated with by the plants that inhabit the ecosystem by the surrounding city that is close by by the surrounding country that is close by

What term is used to describe an animal that eats herbivores? A. primary consumer B. primary producer C. secondary consumer D. secondary producer

Basic unit of structure and function in the nervous system is called

Marie's pulse, breathing rate, and mental alertness have suddenly increased. it is likely that marie is experiencing the: