Essay On Harmful Mutation

Beneficial and Harmful Mutations among Humans

Mutation

A gene mutation is an irreversible change in the sequence of DNA which a gene is made up of. After mutation, the sequence becomes different from that found in most human beings. Mutations are a result of damage to DNA during replication or to the genomes of RNA usually caused by chemical mutagens or radiation. Mutations in genes can either have no effect, alter the product of a gene, or prevent the gene from functioning properly or completely. Mutations can also occur in non-genic regions. Mutations in sex cells can be transmitted to the next generation; mutations in other cells cannot be transmitted. The effects of mutation may be beneficial, harmful or neutral. The DNA fails to copy correctly thus leading to gene mutation.

Harmful Mutations

Harmful mutations result in severe consequences on the health of the person. Some examples of harmful mutations are as follows:

1. Sickle Cell Anemia

It is an example of natural harmful mutation existing in human beings. It is a

These cones are the cells in the retina which distinguish different colors of light. Human beings have three kinds of cones. The two genes which are sensitive to green and red are both present on the X chromosome. The gene for the cone which responds most stoutly to blue color is found on the chromosome 7. A mutation in the red or green gene could shift the range of colors to which it responds. This would make no such difference in men because they would still have three color receptors. But if this takes place in the cone genes of a woman, she would have the red, green and blue on one X chromosome, and a mutated fourth one on the other chromosome. This means that the woman would comprise four different color receptors. She would be a natural “tetrachromat” who is able to distinguish the shades of colors which others cannot tell