Analog signals are like a because there is continuous variation in the data.

1. switch
2. spectrum
3. clock
4. message

Diffusion and osmosis are forms of passive transport

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -