Anesthesia blocks (a. sensory neurons b. motor neurons c. interneurons) from carrying signals to the (a. spinal cord b. muscles c. brain)

Many organs are involved in the processes of keeping the blood and the body clean. when poisonous or harmful substances are in the blood, they are absorbed by the and released in a less harmful form. when wastes are present in the blood, they are filtered out and removed from the body by the

According to the cell theory, which describes cells? a. all organisms are composed of multiple cells. b. all cells have the same structure and function. c. cells are found in everything on earth. d. living organisms are not created spontaneously

The earth formed roughly 4.5 billion years ago, yet evidence of life dates back to about 3.5 billion years ago. which one is not a possible hypothesis of how life on earth arose?