Question

The continuity of life is based on heritable information in the form of DNA. In a short essay (100–150 words), explain how mutations in protein-coding genes and regulatory DNA contribute to Evolution.

Short answer

The new proteins provide necessary adaptations or traits to the individual and pass this information to the next generations, which leads to evolution. Regulatory DNA is a non-coding sequence of DNA. It mainly participates in the expression of genes in the organism. The mutation in regulatory sequences will influence the anatomical features of the organism.

A small difference in a single gene will result in different phenotypic expressions in a population. If these changes are inheritable, it continues to express and cause evolution.

Step-by-step solution

Mutation

The change that occurs suddenly in an individual's genomic sequence and alters the instruction present in DNA is called a mutation.

A mutation can also occur in promotor sequence, binding sites, termination signals, and the structure of enzymes that participate in the cellular process. Spontaneous and inducedare two types of mutation.

Protein-coding genes

DNA contains four types of nucleotides, and they are arranged in numerous ways. The triplet sequence of codons encodes for one amino acid. The arrangement of nucleotides denotes the coded language to synthesize proteins.

When a mutation occurs, the arrangement of codons varies, resulting in the formation of new proteins. As proteins are structural elements in cells, they give new characters.

Regulatory DNA

All cells of the body contain the same DNA. The structure and function of the cell differ due to the expression of genes. Regulatory DNA processes the regulation of genes in a cell. It helps the organism to respond to the surrounding environment. In humans, 80% of the genes are involved in gene regulation.

Effects of mutation on evolution

A mutation is considered a force of evolution as it brings changes in organisms. It creates a new genomic sequence. However, only beneficial mutation leads to evolution. Changes in genes can also cause various genetic disorders and cancer.

Suppose beneficial changes occur in the protein-coding sequence due to mutation, then it leads to minor changes in organisms. Sometimes these changes are not visible to the naked eye; for example, DDT resistance in mosquitoes.

The changes in regulatory DNA due to mutation result in major anatomical or morphological transformations.