Which of the following is significance of dominance

Options

A. Organism with dominant genes are more vital
B. Harmful mutations are not expressed due to dominant gene
C. Heterosis is due to dominant gene
D. All the above

Answer

### Step-by-Step Solution:

1. **Understanding Dominance in Genetics**:
- Dominance refers to the relationship between alleles, where one allele masks the expression of another allele at the same locus. The dominant allele is expressed in the phenotype, while the recessive allele is not.

2. **Analyzing the Options**:
- The options provided are:
1. Organisms with dominant genes are more viable.
2. Harmful mutations are not expressed due to dominant gene.
3. Heterosis is due to dominant gene.
4. All of the above.

3. **Evaluating Each Option**:
- **Option 1**: "Organisms with dominant genes are more viable" - This statement is not universally true as viability can depend on a variety of genetic and environmental factors.
- **Option 2**: "Harmful mutations are not expressed due to dominant gene" - This is a significant aspect of dominance. In heterozygotes (organisms with one dominant and one recessive allele), the dominant allele can mask the expression of the recessive allele, which may carry harmful mutations.
- **Option 3**: "Heterosis is due to dominant gene" - Heterosis, or hybrid vigor, can occur due to a combination of various genetic factors, not solely because of dominant genes.
- **Option 4**: "All of the above" - Since options 1 and 3 are not entirely accurate, this option is also incorrect.

4. **Conclusion**:
- The most accurate and significant statement regarding the significance of dominance is that "harmful mutations are not expressed due to dominant gene." This highlights the protective role of dominant alleles in masking potentially harmful recessive alleles.

5. **Final Answer**:
- The correct option is: **Harmful mutations are not expressed due to dominant gene.**