Question

The parent offspring relationship is -----------% in populations where there is no inbreeding.

• A. 25%
• B. 50%
• C. 75%
• D. 37.5%

Hint:

Parent-offspring and full-sib relationships are both \(50\%\) (\(0.5\)), whereas half-sibs and grandparent-grandchild relationships are \(25\%\) (\(0.25\)) under no inbreeding.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The coefficient of relationship (\(R_{xy}\)) measures the pedigree-based proportion of genes shared between two individuals \(X\) and \(Y\) that are identical by descent.

Step 2: Key Formula or Approach:
The formula for the coefficient of relationship between two individuals \(X\) and \(Y\) under no inbreeding is:
\[ R_{xy} = \sum \left( \frac{1}{2} \right)^L \]
where \(L\) is the number of pedigree pathways connecting them.

Step 3: Detailed Explanation:
For a parent and its offspring:
There is exactly one direct path of generation step between parent (\(P\)) and offspring (\(O\)):
\[ L = 1 \]
\[ R_{PO} = \left( \frac{1}{2} \right)^1 = 0.50 \text{ or } 50\% \]
This means that an offspring inherits exactly \(50\%\) of its genetic material from each parent.

Step 4: Final Answer
Under zero inbreeding, the parent-offspring genetic relationship is \(50\%\).