How could fraternal twins be as different in appearance as michelle and michael, jr., including one having light skin and the other having dark skin?

They are formed from different eggs and sperms.

Explanation:

Fraternal twins appear different a lot of times because they are formed from different eggs and sperms.

Two eggs that are different in their genetic make ups get fertilized by two different sperms which are also different genetically. Hence, two zygotes with different genotypic and phenotypic characteristics results.

This is as opposed to twins that look alike which are formed from the same egg and sperm. A single egg gets fertilized and then divides into two mitotically to give rise to two eggs with the same genetic make up and physical characteristics.

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."