What is the difference between X and Y chromosomes?
Gender is determined by sex chromosomes. XX is associated with female chromosomes and XY are termed as male chromosomes.
The main difference between X and Y chromosomes is that X chromosome is a sex chromosome that determines female gender whereas Y chromosome is a sex chromosome that determines male gender.
Comparison Table (XX vs XY Chromosomes)
Basic Terms | X Chromosome | Y Chromosome |
Meaning | It is a sex chromosome that occurs in paired among female cells and singles among male cells | It is a sex chromosome which is present in male cells |
Sex Determination | Contain genes that determine female gender | Contain genes that determine male gender |
Size and Number | Tend to be bigger and about 155 million base pairs | Tend to be smaller and about 59 million base pair |
Represent | 5 percent of the human genome | 2 percent of the human genome |
Number of Genes | About 100 genes | About 70 genes |
Female and Male genotype | XX genotype | XY genotype |
SYR Gene | Do not contain SYR gene | Contain SYR gene for testes development |
Read More: Difference between Chromatid and Chromosome
What Is X Chromosome?
It is among the two sex chromosomes present in human beings. X chromosomes occur in pair among female cells and single among male cells.
X chromosomes are numerous and they tend to represent 5 percent of the human genome. During embryo development, one X chromosome tends to be inactivated permanently.
What Is Y Chromosome?
It is a sex chromosome present in male cells. They are key determinants of male gender among human beings.
The chromosomes are less in number and they tend to represent about 2 percent of the human genome. Besides that, they contain fewer genes than X chromosomes.
Main Difference between X and Y Chromosomes
- X chromosome contain more genes whereas Y chromosome contain fewer genes
- X chromosomes have 155 base pairs whereas Y chromosomes have 59 base pairs
- X chromosome represent about 5 percent of the human genome whereas the Y chromosome represents about 2 percent of the human genome
- X chromosome contain female sex determination whereas Y chromosome contain male sex determination
- Y chromosome contain SYR gene for testes development whereas X chromosome does not contain SYR gene.
Read More: Difference between Gene and Allele
Similarities between X and Y Chromosome
- Both are sex chromosomes in human beings
- Both contain p arm, q arm and a centromere.
- Both consists of pseudoautosomal regions at both termini
- Both contain homologous chromosomes
Comparison Video
Conclusion
The core difference between X and Y chromosome is that X chromosome is used in determining female sex and Y chromosome in determining male gender.
Female cells have two X chromosomes and male cells have one X chromosome and one Y chromosome. Hence, these chromosomes are regarded as sex chromosomes.
More Sources and References
- Sex Chromosome. NCBI
- Sex of Offspring. Nature