Dna exists in tight coils called a.)genes b.)bases c.)chromosomes d.)mutations

C). Chromosomes

Explanation:

Deoxyribonucleic acid (DNA) is the stored form of the genetic material in most living organisms. DNA is a nucleic acid composed of two polynucleotide chains. It contains the genetic information needed by the organism for its life processes.

However, the DNA is too long to fit into most cells. The cell then devises a means to allow its genetic material fit into its cell. The DNA is coiled around the core of a set of proteins called HISTONES to form a structure known as NUCLEOSOME. The nucleosome is further wrapped around these HISTONES to form another structure called CHROMATIN. The Chromatin then undergoes condensation during cell division to form the X-shaped structure called CHROMOSOME.

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."    

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation: