Question

Given below are two statements:
Statement (I): Inbreeding coefficient through full sib mating reaches 0.986 after 10 generations.
Statement (II): The coefficient of inbreeding was proposed by Sewell Wright.
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

Under full-sib mating, the inbreeding coefficient reaches 0.886 at generation 10 and 0.986 at generation 15.
Sewell Wright is the father of path analysis and the developer of the inbreeding coefficient \( F \).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Inbreeding is the mating of individuals that are more closely related than the average of the population.
The rate of increase in the inbreeding coefficient (\( F \)) per generation depends on the system of mating, with full-sib mating being one of the most intense systems.

Step 2: Detailed Explanation:
Let us evaluate both statements:
Statement (I) is incorrect.
In full-sib mating (brother-sister mating), the inbreeding coefficient increases in each generation.
Calculations show that the inbreeding coefficient (\( F \)) reaches:
- \( 0.886 \) (\( 88.6\% \)) after 10 generations.
- \( 0.986 \) (\( 98.6\% \)) after 15 generations.
Therefore, claiming it reaches \( 0.986 \) after only 10 generations is incorrect.
Statement (II) is correct.
The coefficient of inbreeding (\( F \)) was first formulated and proposed by the geneticist Sewell Wright in 1921 to quantify the degree of inbreeding in an individual.
Therefore, Statement (I) is false, but Statement (II) is true.

Step 3: Final Answer:
Statement (I) is incorrect but Statement (II) is correct.