Question

Artificial selection to obtain cows yielding higher milk output represents

• 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

Answer 1

The correct option is B

Directional as it pushes the mean of the character in one direction

The correct answer is B.

The explanation for the correct answer:

1. Different types of selection - stabilizing, disruptive, directional.
2. When selective pressures select against the two extremes of a trait, the population experiences stabilizing selection.
3. Example- number of offspring produced, human birth weight, etc.
4. In directional selection, one extreme of the trait distribution experiences selection against it.
5. Example- light-colored mice found in dark places (Eg. lava fields) can be spotted very easily by predators. This results in selection for dark-colored mice and a gradual transition of population towards dark mice.
6. In disruptive selection, selection pressures act against individuals in the middle of the trait distribution.
7. Example- beak sizes of finches found on Galapagos island.
8. Here, the focus is on producing cows yielding higher milk output (one extreme of the trait).

Final answer: Artificial selection to obtain cows yielding higher milk output represents Directional as it pushes the mean of the character in one direction