Question

Describe each of the below mutations AND provide an example of each.

1. Behavioral mutations
2. Regulatory mutations
3. Lethal mutation
4. Conditional mutation
5. Neutral mutation

Answer 1

a. Behavioral mutations

A behaviour mutation is a genetic mutation that alters genes that control the way in which an organism behaves, causing their behavioural patterns to change. Example: Mutation in Drosophila melanogaster causing them to behave aggressively.

b. Regulatory mutations

Regulatory mutation is a change in DNA or RNA that alters the expression of other genes by a cell. Mutations in gene regulatory regions are thought to play an important role in the evolution of morphological structures. A regulatory sequence is a segment of a nucleic acid molecule which is capable of increasing or decreasing the expression of specific genes within an organism. Regulation of gene expresssion is an essential feature of all living organisms and viruses. Example: Human genetic disease caused by regulatory mutation.

c. Lethal mutation

Lethal mutation is a type of mutation which can result in the death or reduce significantly the expected longevity of an organism carrying the mutation. Example:During infancy in homozygous recessive individuals, mutation happens and genetic deffect is expressed and brachydactyly(abnormal shortness of the fingers) occures. It is fatal.

d. Conditional mutation

Conditional mutation is a mutation that has wild-type phenotype under certain "permissive" environmental conditions and a mutant phenotype under certain "restrictive" conditions. That is conditional mutations are normal under one condition and abnormal under another. Example: Atemperature sensitive mutation can cause cell death at high temeperature(restrictive condition), but might have no harmful consequences at a lower temperature(permissive condition).

e. Neutral mutation

Neutral mutations are cahnges in DNA sequence that are neither beneficial nor detrimental to the ability of an organism to survive and reproduce. In population genetics, mutations in which natural selection does not affect the spread of the mutation in a species are termed neutral mutations. Example:Change between synonyms in the genetic code which affect non-coding regions of the chromosome, or which result in inconsequential changes such as blood type or eye color in humans.