What is trophic cascade as mentioned in this video titled "how wolves change rivers? "

a• how the rivers flow throughout yellowstone national park.

b• ecological process that starts at top of the food chain and tumbles down to the bottom of the food chain.

c•different types of food chains and food webs.

d• ecological process that starts at the bottom of the food chain and works it way up to the top of the food chain

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h,o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.

15 ! come and answer! a(n) disease is caused by a pathogen and can spread among organisms. a infectious b noninfectious c toxic d contaminated

The united states produces an average of 429 billion pounds of food annually. about 133 billion pounds of that food ends up as waste.the percentage of food that the united states wastes each year is %.