Mutations can affect chromosome number or structure. Among these last ones, deletion and duplication affect affect the number of genes. Translocation and inversion affect gene sequences. A) Translocation B) Deletion C) Inversion D) Duplication.
<h3>What are chromosomic mutations?</h3>
DNA suffers different mutations and changes. These mutations might affect chromosomes by altering a gene sequence or a chromosomal fragment.
There are two types of chromosomal mutations which depend on the mutation type,
- If the mutation affects the number of the chromosomes (haploidy, polyploidy, aneuploidy)
- If the mutation affects the chromosome structure.
Among the mutations that affect the structure of the chromosome, we can mention,
- The ones affecting the number of genes
- Deletion ⇒ Occurs a loss of genes
- Duplication ⇒ The number of genes increases
- The ones affecting the sequence of genes
- Inversion ⇒ genes order or sequence is inverted
- Translocation ⇒ genes are interchanged between chromosomes
In the exposed example,
A) Translocation
There was an interchange of genes between the two involved chromosomes.
One of them started with genes ABC and the other one with genes DE. After the interchage one of them ended with genes AC and the other one with genes DBC.
B) Deletion
The chromosome lost the A gene, which was deleted from the original sequence.
C) Inversion
The original sequence in this chromosome was ABC, and after the inversion the gene order was CBA.
D) Duplication
The original sequence was ABC, and after the duplication event, genes A and B got duplicated and the new sequence was ABABC.
In the attached files you will have an image with further explanation.
Note: You should check if the chromosomal mutations are represented with the same letters I porposed here.
You can learn more about chromosomal mutations at
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