Genetic Mutation: Definition, Steps, Types and Examples

Definition Of Mutation

A mutation is defined as a change in the nucleotide sequence of an organism's DNA. These could either be spontaneous or due to environmental factors and result in changes in different traits and functions in an organism.

What Are Genetic Mutations?

Genetic mutations are changes to the DNA sequence and therefore result in changed genes. These changed genes will then produce variations in traits or functions. Changes at this level are important in evolution because they provide the genetic variation upon which natural selection acts. In medicine, it is an understanding of mutations that enables diagnosis and the development of therapy for the treatment of genetic disorders.

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This Story also Contains

1. Definition Of Mutation
2. What Are Genetic Mutations?
3. Types Of Mutations
4. Causes Of Mutations
5. Effects Of Mutations
6. Mechanisms Of Mutation
7. Mutations In Evolution
8. The Video Recommended On Mutation:

Types Of Mutations

The mutations could, in general, be classified based on the nature and the extent of change in the genetic material.

Point Mutations

• Substitution: Replacement of one nucleotide for another.

• Insertion: One or more nucleotides are added to the DNA sequence.

• Deletion: One or more nucleotides are deleted from the DNA sequence.

Chromosomal Mutations

• Deletion: In which a segment of the chromosome is lost.

• Duplication: That is, the segment of a chromosome is duplicated.

• Inversion: The segment is inverted.

• Translocation: This means the segment of only one chromosome may be translocated onto a nonhomologous chromosome.

Spontaneous Vs. Induced Mutations

• Spontaneous: Those that happen naturally without external influence.

• Induced: In such a way, some are due to the action of exogenous agents, such as chemicals or radiation.

Causes Of Mutations

Several environmental and biological factors can cause mutations in organisms. For instance,

Environmental Factors

• Radiation: UV rays, X-rays, and radioactive materials can cause damage to the DNA.

• Chemicals: Many chemicals like benzene, asbestos, and several drugs are identified as mutagenic.

Biological Factors

• Errors during DNA Replication: It involves those mistakes that take place during the process of cell division.

• Viral Insertions: After infecting the host, viruses introduce their genetic material into the host DNA and produce mutation.

Effects Of Mutations

The effects of mutations will depend on their nature and location in the genome.

Beneficial Mutations

• Selective Advantages: Some of the mutations give advantages to survival or reproductive capabilities.

• Examples: The classic example is resistance to antibiotics in bacteria. Some mutations might allow survival in the presence of antibiotics.

Deleterious Mutations

• Genetic Disorders: Mutation can cause sickle cell anemia, and other severe disorders that cause poor health, such as cystic fibrosis.

Neutral Mutations

• Silent Mutations: There would be no effect on the function of the protein. Such a mutation would seem to have very little or no effect at all on the organism.

Mechanisms Of Mutation

Thus, mutations occur by various mechanisms operative during genetic processes.

Errors In DNA Replication

• Occur when mistakes are made in replicating DNA.

Mutagenic Agents

• Chemical Mutagens: Chemicals acting through a process of chemical interaction.

• Physical Mutagens: Radiations and other physical forces that inflict damage on DNA.

• Biological Agents: Viruses and other organisms that insert their genes into the host DNA.

Repair Mechanisms

• DNA Repair Systems: Cellular mechanisms that reverse DNA damage.

• Role of Enzymes: Details concerning this process are carried out by enzymes like DNA polymerase and ligase.

Mutations In Evolution

These are the raw materials of evolution, upon which Natural Selection works.

In this way, mutations introduce various genetic diversities required for adaptation and evolution. Beneficial mutations, by giving a survival advantage to an organism, are retained and passed on through natural selection.

Examples:

• Darwin's Finches: Beak shapes changed by mutation to eat different food sources.

• Peppered Moths: Industrial melanism in moths due to mutation provided camouflage against predators.

Conclusion

Mutations underline genetic diversity and evolution but are also key to more than a few genetic diseases and the development of medical treatments. The ways for identifying mechanisms and effects of mutation offer means of advancing research and therapeutic strategies. Functional and somatic mutations open new avenues for illustrating prospective future research into the molecular genetics of disease continua and therapeutic strategies and, likewise, evolutionary biology.

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