Changes in DNA are not always considered negative but when the DNA of an organism has a change in it, this is described as a?
2 Answers
This is described as a mutation.
Explanation:
When the DNA sequence of an organism is changed, it is called a genetic mutation.
There are three types of mutations: substitution, insertion, and deletion. Substitution involves replacing a nucleotide with another. Insertion describes adding another nucleotide into a DNA sequence. On the other hand, taking away a nucleotide is called deletion.
Mutation.
Explanation:
A change in the DNA by a random accidental change is called a mutation. The changes in the DNA changes the information carried in the DNA code. These random changes always result in a loss of useable information.
A loss of useable information is not always negative. There are cases where losing information is a good thing but usually the loss of information is a negative.
Some examples where the loss of information is not a negative due to mutations are bacterial resistance to antibodies, blind fish of death valley, and resistance to malaria.
Bacteria gain resistance to antibiotics by losing genetic information. The loss of genetic information removes proteins from the surface of the bacteria that the chemical can attack. In the presence of antibiotics losing this information is a good thing.
The DNA that codes for eye tissue is lost or not expressed in the fish living in total darkness in caves and underground rivers. The loss of the sensitive eye tissue is an advantage where collisions with sharp rocks can cause injury or even death. On the surface the loss of vision would be a bad thing.
In malarial zones the loss of information in the red blood cell ( the substation of a an A for a T in the DNA) causes a weakness in the red blood cell that allows the immune system to enter the red blood cell and kill the malaria sporozoa . In non malarial zones cycle cell anemia caused by this loss of information is a serious disease. ( However malaria is a more serious disease so in a malarial zone this mutation is a good thing. )
Changes in the DNA do not allows have negative effects but are always a loss of information. This is the exact opposite of what is predicted by the Neo Darwinian evolutionary theory
