Answer:
Genetic data of every organism for every trait is stored in the form of unique sequence of nucleotides which we call as genes.
These are the specific nucleotide sequence in genes which ensure the perfect expression of genes for a particular trait. For example: Suppose there is a gene for human height, that has a sequence UGGCGGAGGG etc,
Now if the sequence is correctly transferred to the offspring, the offspring will have the trait perfectly as he has inherited from his parents, if not then there will can be some problems in the height trait of individual.
Changes in DNA during the process of DNA replication. These changes are called a s mutation. Mutations can be of several types like insertions, deletions, duplication and translocation.
Mutations can be lethal or non-lethal depending upon the type of gene or area of the DNA on which they caused change.
For example: There is a disease called Hemophilia which is caused by a mutation or change in the sequence of gene that codes for the synthesis of blood clotting factor.
Due to change of only one nucleotide in this gene, a person can suffer from disease Hemophilia in which his all blood can flow off and waste even on a minor cut because of the lack of expression of gene that codes for blood clotting factor.
Therefore, we can say that changes in DNA sequence can affect the expression of genes in several ways.
Hope it helps!
