Question

What are duplication and translocation in connection with chromosomal mutation?

Answer 1

The alteration or change in the DNA sequence is called mutation. It is a spontaneous process which is inheritable from parents to offspring. Both internal and external factors are responsible for chromosomal mutation.

Complete answer:
To answer this question, we must know about the chromosomal mutation.
Mutation means any change in the DNA sequence. The change can be in the nucleotide bases(A, G, C, T) due to the faulty translation or due to the DNA replication errors or due to any environmental factor like exposure to radiations, chemicals or may be due to microorganisms.
When a chromosome undergoes mutation, it is called chromosomal mutation. In human beings there are 23 pairs of chromosomes in which half is from the mother and half is from the father. Chromosome mutations can be of due to-
Duplication-It happens when the extra copies of genes or regions of chromosome are generated due to which two homologous chromosomes have different genetic material. Gene duplication occurs in the interphase. This duplication leads to evolution of new species.

Translocation- It is an abnormality which happens because a part of chromosome breaks and reattaches to another chromosome. The translocation can be detected by finding the karyotype of the affected cells.

Note: An example of duplication is Pallister Killian syndrome in which the part of the 12th chromosome is duplicated. It is a rare genetic disorder. Chromosomal translocation can cause serious diseases like leukaemia. Down’s syndrome is caused by the translocation in chromosome 24.