Fill in the blank with the appropriate word. ResetHelp The conducts impulses toward the soma. The conducts impulses toward the synaptic terminals. The is the region surrounding the nucleus. The is the enlarged end of an axon. The contains neurotransmitters. The is a cluster of RER and free ribosomes. The is another term for the soma of a neuron. The is the membrane of the axon. The is a cell that forms the blood 13brain barrier. The is a fine branch of an axon.

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."