Correct option is D
Detailed Explanation:
Statement A: Quantitative traits are characterized by discontinuous variations in the phenotype.
- Incorrect: Quantitative traits typically show continuous variation (e.g., height, weight, etc.), as they are influenced by many genes and environmental factors. Discontinuous traits are more characteristic of qualitative traits, which exhibit clear categories (e.g., Mendelian traits). Therefore, Statement A is incorrect.
Statement B: Polygenic traits never show a normal distribution of phenotypic variability.
- Incorrect: Polygenic traits (traits controlled by multiple genes) usually show a normal distribution of phenotypic variability. This is because the combined effect of many genes typically results in a bell-shaped curve of variation, which is characteristic of a normal distribution. Therefore, Statement B is incorrect.
Statement C: Association mapping captures wider genetic diversity than biparental linkage mapping.
- Correct: Association mapping (which is commonly used in genome-wide association studies or GWAS) typically captures a wider genetic diversity because it is based on natural populations with a broad genetic variation. On the other hand, biparental linkage mapping is generally restricted to the genetic variation between two parents. Therefore, Statement C is correct.
Statement D: Bulked segregant analysis can be used for mapping of monogenic qualitative traits.
- Correct: Bulked segregant analysis (BSA) is an efficient method used for mapping monogenic traits (traits controlled by a single gene). It involves pooling DNA from individuals that show extreme phenotypes, allowing for the identification of genetic markers linked to the trait. Therefore, Statement D is correct.
