Question

Is DNA located in chromosomes?

Answer 1

Hint: Deoxyribo nucleic acid also known as DNA, a complex molecule which contains all the essential knowledge for building and maintenance of an organism. Chromosome is a structure found in the nucleus made of proteins and DNA.

Complete answer:

• DNA is a complex molecule which is present in each and every cell of a multicellular organism. Deoxyribo nucleic acid, also known as DNA, contains the necessary information for the formation and maintenance of organisms. 
• Some part of DNA is present in mitochondria while most of the DNA is present inside the nucleus. The information in DNA is stored in four forms: adenine (A), guanine (G), thymine (T), cytosine(C).
  Inside the nucleus of each and every cell, a chromosome is a thread-like structure in which DNA is packed. DNA is tightly coiled around the chromosome multiple times which are held by proteins called histone proteins. 
• When the cell is not dividing, chromosomes are not visible even from the microscope. However, during division of a cell, the chromatin threads condense itself to form chromosomes which are visible under a microscope.
  There is a constriction point known as centromere, which divides the chromosome into two parts more commonly known as arms. 
• Position of the centromere gives the chromosome a specific shape which helps in location of specific genes. Short arm is known as the “p arm” and the long arm is known as the “q arm.”
  Hence, we can say that DNA is located in chromosomes.
  

The following figure shows that DNA is located in chromosomes:

Note: Prokaryotes (bacteria and archaea), on the other hand, only store their DNA in the cytoplasm, in circular chromosomes. Chromatin proteins, such as histones, compact and organize DNA within eukaryotic chromosomes. These compacting structures help control which parts of the DNA are transcribed by guiding the interactions between DNA and other proteins.