How is a food web a limited model in regards to showing energy transfer?

The energy of blowing wind can be harnessed to create electricity. why is wind considered a renewable energy source? a) wind does not cause destruction of the environment.b) wind turns the blades of a windmill that creates electricity.c) wind provides only a very small amount of electricity to the united states.d) wind comes from atmospheric conditions that are available indefinitely.

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

How far away is the nearest black hole from earth?