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Difference Between Autosomes and Sex Chromosomes


If you’re among people looking for the difference between autosomes and sex chromosomes, know that it’s the right platform! Living organisms can be multicellular or unicellular, but in either case, they rely on their cellular properties. A cell is the central part of a living body containing organelles like mitochondria, chloroplast, nucleus, etc. All organelles are specified in their functioning, and so does a nucleus, which performs a primary role.

The nucleus has a unique genetic material called DNA, enclosed in chromosomes. There is a total of 46 chromosomes in the human body, or you can call it a pair of 23. Two of the 46 chromosomes are sex chromosomes, whereas the rest are autosomes. Let us look into the article below to grab detailed differences between the two.

Comparison Chart

ComparisonAutosomesSex Chromosomes
FunctionIn determining the
somatic characteristics
In determining the
sex-linked traits
HomologousPartially homologous
Chromosomal PairsBoth arms are
of equal length
Y-chromosome is shorter
Total Pairs22 pairs1 pair
of Centromere
The position is fixedThe position may vary
SimilarityIdentical autosomesSize, shape, and
characteristics may vary
LabelingIn numericAs XY, ZO, and XO

Autosomes – Brief Explanation

All types of chromosomes other than sex chromosomes are autosomes that look after a body’s somatic characteristics. Autosomes are classified as chromosomes 1, 2, and so on, as per their appearances, sizes, and similar properties. These fixed pairs of autosomes are linked to regulating the genetic information of a body. It means whatever characteristics an offspring gets from its parents are due to the autosomes.

Each of the autosomal pairs is of equal length and even the centromere is settled at a set position. When a cell is about to divide during mitosis, each chromosome duplicates to segregate in the daughter cells. Therefore, all these cells get equal chromosomal pairs having sufficient genetic material.


Sex Chromosomes – Brief Explanation

The two distinguishing chromosomes that take part in deciding the gender of a child are called sex chromosomes. These chromosomes are largely classified as X and Y. A female possesses two X chromosomes, while a male has a combination of both X and Y.

There are usually two arms of a chromosome. All the Y chromosomes contain one short and the other long arm. On the other hand, the X is quite similar to the autosomal chromosome. That is why there are more than 300 genes in the DNA of an X chromosome while the other shows up with a few of them being smaller in size.

Find Out the Differences Between Autosomes and Sex Chromosomes



All those chromosomes playing a vital role in determining the physical properties of a human are called autosomes.

Sex Chromosomes

These are also called Allosomes. Sex Chromosomes or Allosomes fundamentally play a part in deciding the sex characteristics in a body.

Maximum Chromosomes in Our Genome


These chromosomes are present in the majority of a genome as they determine the characteristics of all parts of a human body.

Sex Chromosomes

These sex-linked chromosomes are very few in a genome.

Labeled As


Scientists have labeled autosomes as 1, 2, 3, and so on up till 22.

Sex Chromosomes

These chromosomes are identified as XY, XO, ZO, and ZW.

Nature of Chromosomes


The 22 pairs or 44 autosomal chromosomes are homologous by nature.

Sex Chromosomes

These sex chromosomes, XY and XX, are non-homologous and homologous, respectively.


Type of Inheritance


These chromosomes function on the principle of Mendel’s Law of inheritance. It means that autosomal cells act according to dominant and recessive alleles.

Sex Chromosomes

There is no role of Mendelian inheritance seen in sex chromosomes. It means that these cells can involve the characteristics of more than one gene.

Position of Centromere



Centromeres are fixed at a position in autosomes.

Sex Chromosomes

Allosomes have non-identical centromeres; hence they can locate anywhere, depending upon the need.

Number of Genes Present


In autosomes, the number of genes can differ and range from 200 to even 2000.

Sex Chromosomes

There are a limited number of genes in sex chromosomes, such that X has almost 300 genes and Y consists of a few.


As we concluded the difference between autosomes and sex chromosomes, their functioning is all clear now. There is not enough involvement of sex chromosomes in processes of natural selection, evolution, mutation, etc., due to being heteromorphic., mutation, etc., due to being heteromorphic. Whereas the autosomes equally divide into daughter cells through karyokinesis and cytokinesis, at the time of mitosis. Thus, it presents a chief role in evolutionary methods. Either its autosomes or sex chromosomes both act to transfer the hereditary material to the offspring.

2 thoughts on “Difference Between Autosomes and Sex Chromosomes”

    1. Out of the two major types of chromosomes, sex chromosomes develop in pairs to determine the gender of a person. They can either be identified as XY for male, and XX for female.

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