Question

Polygenic traits, traits determined by more than one gene, often have phenotypes that are distributed on a bell curve. _______ occurs when one end of the bell curve is better adapted to the environment than the other.

Answer 1

Answer:   directional selection

Explanation: Directional selection occurs when one end of the bell curve has a better fit than the other end. The end that has preferable traits in relation to the environment won't always be the same. The environment can change, and then the opposite end of the bell curve might become preferable.

Answer 2

Answer:

1. directional selection
2. Hardy-Weinberg equilibrium
3. sympatric
4. This is allopatric speciation.
5. This is an example of stabilizing selection in a population because the organisms in the middle of the population have the best fitness for their environment.
6. The five conditions impacting this equilibrium are: mutations, nonrandom mating, genetic drift, migration, and natural selection.
7. Natural selection impacts single-gene traits because of the possible extinction of one trait or increase of another trait. If a trait is found to be not preferable in that environment, it could be eliminated through natural selection.
8. The total allele frequency in the Hardy-Weinberg equilibrium has to equal 1.

Explanation: