Artificial selection to obtain cows yielding higher milk output represents
Answer: (B) Directional as it pushes the mean of the character in one direction. Answer: (B) Directional as it pushes the mean of the character in one direction.
- A.Stabilizing selection as it stabilizes this character in the population
- B.Directional as it pushes the mean of the character in one direction✓
- C.Disruptive as it splits the population into two one yielding higher output and the other lower output
- D.Stabilizing followed by disruptive as it stabilizes the population to produce higher yielding cows
Correct Answer
(B) Directional as it pushes the mean of the character in one direction
Solution & Explanation
Answer: (B) Directional as it pushes the mean of the character in one direction. Artificial selection for cows yielding higher milk output continuously favours individuals at one extreme (high yield), shifting the population mean toward that end over generations. This matches directional selection, where more individuals acquire a value other than the mean character value. It is not stabilising (which favours the mean) or disruptive (which favours both extremes). NCERT Reference: Ch 6 Evolution, p.121, lines 35–36: "directional change (more individuals acquire value other than the mean character value)".