<u>Answer</u>: Natural selection.
<u>Explanation</u>:
- The concept of <em>natural selection</em> was given by <em>Charles Darwin.</em>
- According to this concept, in a given environment the organisms that possess <em>better adaptations</em> have<em> higher chances of survival</em> and, leave behind a <em>greater number of progenies</em>.
- When malaria outbreak occurs, the allele frequencies change and only the organisms that possess the alleles which help them to <em>survive</em> this outbreak due to resistance against malarial infection will be selected by nature and<em> hence, this is an example of natural selection.</em>
The removal of the producers would cause the collapse of the entire food web. Primary consumers or herbivores, which feed on producers directly, would die off.
The conditions depend on the density level of the snow.
Another reason is the imperfect data gathering especially if initial results are only gathered.
The third reason is that computer models still find it difficult to see small scale phenomena.
Answer:
c) A study of how disease rates vary among different population groups
Explanation:
Epidemiology is the systematic and scientific study of the distribution of the health-related issue in a specified population.
The Epidemiologists studies the disease and its cause in a population by the collection of the data which gives an insight in the distribution of the health issues in the population living from a small area like school to a country.
The epidemiological studies help the society by reducing the risk of the negative health outcomes, in spreading awareness about the health issues and in framing the health policies.
Thus, Option-C is the correct answer.
