DNA, RNA, Chromosomes, and Genes


How are chromosomes assembled?

Chromosomes are assembled on a scaffold of proteins (histones) that allow DNA to be tightly packed. Five major types of histones exist, all of which have a positive charge; the positive charges of the histones attract the negative charges on the phosphates of DNA, thus holding the DNA in contact with the histones. These thicker strands of DNA and proteins are called chromatin. Chromatin is then packed to form the familiar structure of a chromosome. During mitosis, chromosomes acquire characteristic shapes that allow them to be counted and identified.


This is a web preview of the "The Handy Biology Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App