Carbon is present in the atmosphere as
carbon dioxide
carbonate ion
carbon dust
carbon monoxide

carbon dioxide

Explanation:

Carbon is present in both the hydrosphere and the atmosphere as carbon dioxide (CO2). This compound is derived from the combustion of plant remains and the respiration of plants and animals. CO2 is absorbed by chlorophyllated plants and chemosynthesizing bacteria and is used to form carbonated organic compounds (cellulose and starch).

Part of this gas returns directly to the atmosphere by breathing in the plant. The plants are ingested by the animals. From the combustion of these foods in the animals' organism, CO2 returns to the atmosphere, or when these animals die, it will be part of the organic debris that, due to the death of chlorophyllated vegetables and bacteria, will form vegetable debris, which upon combustion will return the CO2 to the atmosphere.

you are certainly talking about this picture:

a: is the label of the white square, it is showing the  replication fork, formed by helicase (d) ==> so it is the site of dna separation and replication 

b: is a new dna brand that is following directly the replication fork, so it is continuous ==> built continuously from 5' to 3

c: dna polymerase cannot replicate dna on its own, it needs the of their proteins, and one of them plays the role of a clamp which fixes  the dna with the dna template and increases  the processivity of the enzyme. ==>   stops polymerase from falling off the  template.

d: is the enzyme responsible for forming the replication fork (helicase) ==> unwinds and separates dna into two strands

e: is the delayed strand, it is built  in the opposite sense of the helicase, so dna will be built in fragments ==> built  fragments from 5' to 3 joins

and finally f: is the enzyme that builds  the new dna strand (dna polymerase) ==>   adds nucleotides to make a new dna helix.

credit: gradman555p98x9p

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