How do barnacles get nutrients? O They catch small land insects.
O They attach themselves to seaweed and feed on it.
O They filter microscopic organisms from the waters.
O They crawl upon the ocean floor and feed on parasites.

The answer is: They filter microscopic organisms from the waters.

Explanation:

Barnacles are filter feeders, which is why they are usually on dock poles and non-moving structures underwater. They do not need to travel to get food, because it comes to them!

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."