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. The robot's cardiac cells, working together in synchrony, could be considered at what level in life's hierarchy of organization?
a. organelle
b. organism
c. organ system
d. tissue

d. tissue

Explanation:

There are several levels of organization of life which starts from the functional unit of life called cell.Cells are made of a combination of macromolecules that consist of atoms. Several cells associate together to perform one or more specific functions at the tissue level. The tissue level is made up of similar cells that carry out similar task or functions. The robot’s cardiac cells that work together in synchrony could be considered at the tissue level.

trachea, alveoli, lung capillaries, arteries

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what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.