Question

If a part of chromosome gets separated and reattached in reverse position to the same chromosome, the mutation is called
A. Inversion
B. Transversion
C. Translocation
D. Gene mutation

Answer 1

A thread-like structure or segment of DNA is called a chromosome. The DNA stands for deoxyribonucleic acid. The chromosomes are located in the nucleus of the cell. The chromosomes consist of proteins and a segment of DNA.

Complete answer:
The word chromosome has arrived from the word Chromatin. A chromatin is the material inside the chromosome that is made up of proteins and DNA. The chromosome is present inside the nucleus of the cell. The chromosome of the cell contains DNA that stands for Deoxyribonucleic acid. The DNA carries hereditary information from the parents to the offspring. The DNA is present in the nucleus of the cell so it is the carrier of genetic information. The major proteins that are involved in chromatins are the histones. The histones help in the package of DNA in the form of octamers. The word octamer works from eight molecules where ‘octa’ stands for eight. The DNA is arranged in such a way in the chromosome such that the genetic material along with histones is held tightly inside the nucleus.
The change or alteration in the sequence of nucleotides on the surface of chromosomes that results in sudden or abrupt change in the characters is called the mutation. The phenomenon in which the chromosomes disintegrate and then arrange end to end to form a segment is called inversion. The type of substitution in which a purine nucleotide is substituted with pyrimidine or the pyrimidine is substituted with purine is called transversion. The phenomenon in which a segment of chromosome gets broken from its original position and is located in another position that lies within the same chromosome or with another chromosome is called translocation.

Hence, the correct answer is option (A)

Note: Chromosomes can be seen with the help of a light microscope. These chromosomes are visible clearly only during the metaphase stage of cell division; this is because the chromosomes get aligned in the centre and are present in condensed form. Some chromosomes help in determining the sex of the person this are called sex chromosomes namely X chromosome and Y chromosome.