Answer:
There are four categories for air masses: arctic, tropical, polar and equatorial. Arctic air masses form in the Arctic region and are very cold.
Answer: DNA is a polymer of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base
Explanation:
Every molecule in the human body are formed by the chains of particular substances. These components are arranged orderly as linked chains to give the structure called DNA.
The components include nucleotides—this is also considered the chemical substance in the human body which helps in the formation.
In this formation of chains, nitrogenous bases will also be linked to form a polymer of DNA.