Answer and Explanation: The figure below shows the doses of BPA administered to the female mice over time.
An experiment is used to determine cause and effect among variables. When the research is for the impact of a treatment, researchers randomly separate individuals in two groups:
- <em><u>Control</u></em> <em><u>Group</u></em> doesn't receive any treament or a placebo or a treatment whose outcome is already known;
- <em><u>Treatment</u></em> <em><u>Group</u></em> receives the treatment;
For the female mice on the image below, in the First Group is not injected any dosage of BPA, so they are the control group, while the <u>others</u> are <u>treatment group</u>.
The variables in a experiment are classified as independents or dependents:
- <em><u>Independent</u></em> <em><u>Variable</u></em> is the cause;
- <em><u>Dependent</u></em> <em><u>Variable</u></em> is the effect;
For the BPA research, since it is the effect of BPA over time on the mice's cells it is being investigated, <u>dosage</u> of BPA is the <u>independent</u> variable and <em>time</em> is the <em>dependent</em> variable.
Answer:
Genetic drift
Explanation:
Genetic drift is defined as the random change in allelic frequencies from one generation to the other.
Genetic drift is an evolutionary mechanism in which the allelic frequencies in a population change through many generations. Its effects are harder in a small-sized population, meaning that this effect is inversely proportional to the population size. Genetic drift results in some alleles loss, even those that are beneficial for the population, and the fixation of some other alleles by an increase in their frequencies. The final consequence is to <u>randomly</u> fixate one of the alleles. Low-frequency alleles are the most likely to be lost. Genetic drift results in a loss of genetic variability within a population.
Genetic drift has important effects on a population when this last one reduces its size dramatically because of a disaster -bottleneck effect- or because of a population split -founder effect-.
Answer:
from 60 to 100 beats per minute