B.7C Mutations_Approaching – 02
On a Saturday evening, Ethan was watching a movie about superheroes. As he watched he wondered, can mutations really give superpowers? At school, they are studying the DNA. He knows that DNA is transcribed to RNA and then translated to form a protein. If there is a change in your DNA, there will be a change in the protein produced, and so there will be a change in…you! SO, is it possible…?
He decided to ask his neighbor, Dr. Wallace who teaches genetics at the local University.
On Sunday, Ethan was very excited to be with Dr.Wallace. Dr. Wallace sat down with him and began to explain.
Dr. Wallace said that mutations are changes in the DNA. Most mutations have no effect on the organism. Some mutations can help and others can hurt the organism. The different forms of life that we see today are due to changes in the DNA.
DNA is read in a sequence of three bases. Each of these sequences is a codon. Sequencing of bases is like writing a sentence. If few of the letters in the sentence, “THE MAN SAW THE FAT DOG.” is changed by chance, it would be hard to understand the meaning. In the same way, when there is a mutation, the message in the DNA is changed.
There are two basic types of mutations. They are gene mutation and chromosomal mutation. In gene mutation, there is a change in the nucleotide sequence of the gene. In chromosomal mutation, there is a change in parts of the chromosomes.

Mutation at a single point in the nucleotide base are point mutations. Substitution is one type of point mutation. In substitution, one base is changed into a different base. The effect of the point mutation depends on the point where the change has happened. For example, if the change still produces the same protein, there is no effect. But if the change produces a completely different protein, it could have a major effect.
Insertion and deletion are other types of point mutations. In these mutations, one base is inserted into or deleted from the sequence. This changes the sequence of reading the codons. These types of mutations are also known as frameshift. Frameshift mutation changes the reading frame of the genetic message. This can form a different type of protein with a different function.