CHROMOSOMES
A chromosome is a structure made out of DNA as well as RNA and proteins. Inside chromosomes is one coiled piece of DNA containing many genes and nucleatoid sequences. Most all of an organisms genes are inside chromosomes. They serve as a package that keeps DNA tightly wound. Without chromosomes the long strands of DNA would not be able to fit inside the nucleus.
The number of chromosomes depends on the organism. Humans generally have 23 pairs (46 individuals) per cell. 22 of these are autosomes meaning they look the same in both male and female. The 23rd pair are sex chromosomes, meaning they differ between males and females. Females have XX chromosomes and males have XY.
image source: http://www.rsc.org
The number of chromosomes depends on the organism. Humans generally have 23 pairs (46 individuals) per cell. 22 of these are autosomes meaning they look the same in both male and female. The 23rd pair are sex chromosomes, meaning they differ between males and females. Females have XX chromosomes and males have XY.
image source: http://www.rsc.org