IMP TOPIC .... Chromosomal Theory of Inheritance ........ | Gaurav Gupta sir
IMP TOPIC ....
Chromosomal Theory of Inheritance ........
Chromosomal theory of inheritance was given by Walter Sutton in 1902. This theory also explains the linear structure of chromosomes with genes in particular sites which was mentioned as loci while Boveri also studied this theory separately. So, this theory is also known as the Boveri-Sutton chromosome theory. According to this theory-
(i) Genes are found at specific locations on the chromosomes.
(ii) During meiosis the homologous chromosomes separate.
(iii) After fertilization the number of chromosomes becomes diploid.
(iv) Chromosomes segregate as well as assort independently.
Mutation...
The sudden changes in the sequence of DNA are known as mutations. The changes in the DNA may be heritable and will be passed onto the next generations affecting both the genotype, as well as the phenotype of an individual. The different types of mutation are frameshift mutations, insertions, deletions, duplications, substitutions, etc. Mutations may be harmful or may not affect at all.
(i) The addition or deletion of DNA bases will lead to changes in the reading frame called the Frameshift mutations.
(ii) The addition of DNA bases is known as insertions.
(iii) Removal of DNA bases is known as deletions.
(iv) If a piece of DNA is copied for more than one time is known as duplication.
Thus, these mutations will lead to a change in the DNA sequence resulting in the formation of the wrong protein.
