The major cause of evolution of genes and protein is

Options

A. Point mutation
B. chromosomal aberration
C. sexual reproduction
D. gene duplication and divergence

Answer

To determine the major cause of evolution of genes and proteins, we can analyze the provided options step by step:

1. **Understanding the Options**:
- **A. Point Mutation**: This refers to a change in a single nucleotide in a gene, which can lead to a change in the amino acid sequence of a protein. This alteration can result in variability among individuals, which is essential for evolution.
- **B. Chromosomal Aberration**: This involves changes in the structure or number of chromosomes, which can also lead to genetic diversity but is not as direct in affecting individual genes and proteins as point mutations.
- **C. Sexual Reproduction**: While sexual reproduction promotes genetic variability through recombination, it does not directly cause changes in genes or proteins.
- **D. Gene Duplication and Divergence**: This process can lead to the evolution of new functions in proteins but is not as immediate as point mutations in altering existing genes.

2. **Analyzing Point Mutation**:
- Point mutations can lead to a single nucleotide change in a gene, which may result in a single amino acid change in the protein produced. This change can create variability, which is a fundamental aspect of evolution.

3. **Conclusion**:
- Among the options provided, point mutation is the most direct and significant cause of evolution at the level of genes and proteins. It introduces variability that can be acted upon by natural selection, leading to evolutionary changes.

Thus, the major cause of evolution of genes and proteins is **A. Point Mutation**.