Answer:
Directional Selection
Explanation:
The type of natural selection that favors one of the extreme phenotypes over the intermediate and another extreme phenotype is called directional selection. Here, the extreme phenotype exhibits better survival and reproductive fitness over the other phenotypic ranges.
In the given example, the frequency of the heat-tolerant allele in microbes is shown to increase under the conditions of higher temperatures of the water of the springs in which they live.
When the temperature of spring water is increased, the frequency of the heat-tolerant allele is reduced and is increased again upon an increase in water temperature.
Since the natural selection favors the extreme phenotype (microbes with heat tolerance) when the spring water exhibits higher temperatures, it is directional selection.
Answer:
b. a person has an emotional need for a drug
Insecticide resistance is the development by insects of resistance to insecticides. It is the ability an insect can either get naturally or by mutations to withstand the effects of insecticides aka becoming resistant.
