Difference Between Autosomes and Sex Chromosomes
May 27, 2023 
written by Sidra Batool
written by Sidra BatoolThe main difference between autosomes and sex chromosomes is the variation in the genes they carry. Autosomes contain genes responsible for determining somatic characteristics, while sex chromosomes carry genes that determine an organism’s sex and sex-related traits.
Autosomes vs. Sex Chromosomes
Here are the main differences between Autosomes and Sex Chromosomes:
| Aspect | Autosomes | Sex Chromosomes |
|---|---|---|
| Definition | Chromosomes that do not determine an individual’s sex | Chromosomes that determine an individual’s sex |
| Number | Present in pairs, usually two copies of each autosome | Present in pairs, with two copies in females (XX) and one copy in males (XY) |
| Genetic Inheritance | Inherited equally by both males and females | Inherited differently between males and females |
| Gene Composition | Contains genes responsible for general traits and characteristics | Contains genes responsible for sexual development and reproduction |
| Role in Sex Determination | Not involved in determining the individual’s sex | One of the sex chromosomes determines the individual’s sex |
| Determining Traits | Autosomes contribute to the development of somatic traits | Sex chromosomes play a role in determining gender and sex-related traits |
| Chromosome Size | All autosomes are of the same size (homologous) | Sex chromosomes have different sizes (heteromorphic) |
| Labeling | Autosomes are labeled with numbers (1 to 22) | Sex chromosomes are labeled with letters (e.g., XY, ZW) |
| Homology | Autosomes are homologous, with identical centromere positions | Female sex chromosomes (XX) are homologous (homomorphic), while male sex chromosomes (XY) are non-homologous (heteromorphic) |
| Gene Quantity | Autosomes carry a variable number of genes (200 to 2000) | X chromosome contains more than 300 genes, while Y chromosome carries fewer genes due to its smaller size |
| Inheritance Patterns | Autosomal disorders follow Mendelian inheritance patterns | Sex-linked disorders exhibit non-Mendelian inheritance associated with sex chromosomes |
| Examples | Chromosome pairs 1 to 22 in humans | In humans, the X and Y chromosomes |
File Under:
Leave a Reply