Inversion
Here, the chromosome is rearranged or reversed from both ends. Usually, small inversional changes go unnoticed. Also, they hardly create any abnormalities. Inversion is simply the rearrangement of genetic sequences, and it does not involve loss of any genetic information. Mostly, it happens within a single chromosome. The two types of chromosomal inversion are –
- Paracentric inversion – Does not include the centromere, the chromosomal breaks occurs in one arm
- Pericentric inversion – Includes the centromere; the break occurs in the arms.
Translocation
It is a chromosomal rearrangement involving the switching of fragments between two nonhomologous chromosomes. A fusion gene is usually formed as a result of translocation. This type of chromosomal rearrangement can cause several abnormalities like down’s syndrome, cancer, and infertility. The different types of chromosomal translocation are –
- Reciprocal translocation – Exchange or translocation between two non-homologous chromosomes.
- Nonreciprocal translocation – One-way translocation of segment from one non-homologous chromosome to another.
- Robertsonian translocation – It involves translocation between two acrocentric chromosomes, at or near the point of centromere.
Difference between Inversion and Translocation
|
Inversion |
Translocation |
|---|---|
|
It is a chromosomal rearrangement where the fragment is reversed from end to end. |
It is a chromosomal rearrangement involving the exchange of information between two non homologous chromosomes. |
|
It involves only one chromosome. |
It involves two chromosomes. |
|
It does not cause adverse effects unless there is a missing or wrong gene during inversion. |
It causes diseases like down’s syndrome, cancer and infertility. |
|
Inversion can be pericentric or paracentric. |
Translocation can be reciprocal, nonreciprocal or robertsonian. |
Explore: Difference between Paracentric and Pericentric Inversion
Frequently Asked Questions on Difference between Inversion and Translocation
What is chromosomal duplication?
It is a mechanism by which a region of the chromosome is duplicated or amplified. The duplication process results in extra genetic material. It usually arises as a result of an error in DNA replication or repair mechanism.
What is the homologous and non-homologous chromosome?
Homologous chromosomes are those with the same gene sequences, paired at the time of meiosis. They have the same gene sequences derived from each parent. Non-homologous chromosomes are those which do not belong to the same pair.
What type of translocation causes Down’s syndrome?
Down’s syndrome is caused by Robertsonian translocation between the long arm of chromosome 21 and chromosome 14. This usually happens in less than 5% of the population.
Also Read: Difference between Translocation and Crossing Over
Keep exploring BYJU’S Biology for more exciting topics
Comments