Question

What are the two types of mutation?

Answer 1

Mutation and its types:

1. A mutation is a sudden, heritable change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light, radiation, and smoke.
2. For example, the disorder of sickle cell anemia is caused by a mutation in the gene that instructs the building of a protein called hemoglobin.
3. This causes the red blood cells to become an abnormal, rigid, sickle shape.
4. Genetic variations in the body are caused by mutation.

Types of mutation:

1. Gene Mutation:

1. When a mutation in DNA occurs, it means a change in one or more DNA bases takes place. Different proteins are then produced, which affect an organism’s traits.
2. It is subdivided into two parts:
3. A point mutation is a genetic mutation where a single nucleotide base is changed, inserted, or deleted from a DNA or RNA sequence of an organism's genome.
4. It commonly occurs when one base is substituted for the other.
5. Example: Cystic fibrosis.
6. A frame-shift mutation is a genetic mutation caused by a deletion or insertion in a DNA sequence that causes a shift in the way the sequence is read.
7. DNA (or RNA) nucleotide sequences are read three nucleotides at a time in units called codons, and each codon corresponds to a specific amino acid or stops signal.
8. Frame-shift mutations arise when the normal sequence of codons is disrupted by the insertion or deletion of one or more nucleotides, provided that the number of nucleotides added or removed is not a multiple of three.

2. Chromosomal Mutation:

1. Chromosome mutations are alterations occurring in chromosomes that typically result from errors during nuclear division or from mutagens.
2. Unlike a gene mutation that alters a single gene or a larger segment of DNA on a chromosome, chromosome mutations change and impact the entire chromosome.
3. Down syndrome and Turner syndrome are examples of chromosomal mutations.

3. Somatic Mutation:

1. The mutation is occurring in the somatic cells of a multicellular organism rather than the germinating cell, i.e; the egg and the sperm are called a somatic mutation.
2. Somatic mutations result from environmental changes like Ultraviolet radiation and several other chemicals and artificial substances. The mutation affects all the cells from the mutated cell. These mutations can occur in the major part of the body of an organism or plant. This causes many diseases including cancer.
3. Because these get transferred through somatic cells only, the mutation will not be passed to the next generation through sexual reproduction.
4. Some of the somatic mutation examples include navel oranges and red apples.

4. Germinal Mutation:

1. In germinal mutation, the alteration in the germinal cells causes the mutation.
2. Germ cells are the ones that give rise to gametes. So this mutation can be passed by sexual means.
3. This can occur before fertilization and also during different stages of the zygote formation and its progression towards a child.