Question

Match LIST-I with LIST-II
\begin{tabularx}{0.9\textwidth}{|l|X|l|X|} \hline \multicolumn{2}{|c|}{LIST-I} & \multicolumn{2}{c|}{LIST-II}
\multicolumn{2}{|c|}{Law/Principle/Gene interaction} & \multicolumn{2}{c|}{Genes distribution/Ratio}
\hline A. & Law of segregation & I. & 12:3:1
B. & Principle of independent assortment & II. & Genes are distributed without mixing.
C. & Complementary gene interaction & III. & Genes on different chromosomes are distributed independently during meiosis.
D. & Dominant epistasis & IV. & 9:7
\hline \end{tabularx}
Choose the most appropriate answer from the options given below:

• A. A - II, B - III, C - IV, D - I
• B. A - I, B - III, C - II, D - IV
• C. A - II, B - I, C - IV, D - III
• D. A - III, B - IV, C - I, D - II

Hint:

For matching questions involving genetic ratios, it's highly beneficial to memorize the key dihybrid cross ratios:

\textbf{9:3:3:1} - Standard Independent Assortment
\textbf{9:7} - Complementary Genes
\textbf{12:3:1} - Dominant Epistasis
\textbf{9:3:4} - Recessive Epistasis
\textbf{15:1} - Duplicate Dominant Genes \end{itemize}

Answer 1

The Correct Option is A

Step 1: Concept Overview:
The question tests knowledge of genetic principles and gene interactions by requiring the correct matching of terms with their definitions or resulting phenotypic ratios.

Step 2: Detailed Matching Rationale:
- A. Law of Segregation: This law dictates allele separation during gamete formation, ensuring each gamete receives only one allele per gene. This aligns with the concept that alleles don't blend. Therefore, A corresponds to II.
- B. Principle of Independent Assortment: This principle explains that alleles of genes on different chromosomes are inherited independently. This matches the description of genes on different chromosomes being independently distributed during meiosis. Hence, B corresponds to III.
- C. Complementary Gene Interaction: This interaction involves two genes working together for a single trait, requiring a dominant allele from both genes for the dominant phenotype. This interaction results in a 9:7 phenotypic ratio in a dihybrid cross. Consequently, C corresponds to IV.
- D. Dominant Epistasis: This occurs when one dominant allele masks the expression of another gene's alleles. A dihybrid cross with dominant epistasis yields a 12:3:1 phenotypic ratio. Thus, D corresponds to I.

Step 3: Solution:
The correct matching is A-II, B-III, C-IV, D-I, which is option (A).