a chromosome is a long DNA molecule with part or all of the genetic material of an organism. most eukaryotic chromosomes include packaging proteins called histones which aided by chaperone proteins bind to and condense the DNA molecule to maintain its integrity.
The amount of CO2 found in the atmosphere varies over the course of a year. Much of this variation happens because of the role of plants in the carbon cycle. Respiration happens all the time, but dominates during the colder months of the year, resulting in higher CO2 levels in the atmosphere during those months.
