The answer should be the letter D
Answer:
Darwin proposed the theory of natural selection to explain the process of evolution. According to Darwin’s theory of natural selection, all organisms have the potential to reproduce limitlessly irrespective of the fact that each species maintain a constant density over time. However, the struggle for existence, i.e. the competition among individuals for available resources to survive and reproduce, put a check on species density (D) and maintains it at a constant level (B). Survival of fittest is unequal ability of individuals to survive and reproduce based on suitability of their inherited characters to prevailing environmental conditions (A). It imparts the reproductive advantage to certain organisms which account for major part of the gene pool of the species. Thus, natural selection favors the individual with survival and/or reproductive advantage over others under existing environmental condition (E). Thus, the correct answer is option C.
Answer:
Control comes with regulating the amount of radiation that a patient is exposed to (using a dosimeter) while accomplishing the task required – such as taking radiology images or irradiating tumor cells. Regulating radiation levels include ensuring the right distance between the patient and radiation source and implementing requisite shielding techniques. The time duration for exposre should be short and radiation sources should also be labeled accordingly.
The area of land<span> that is drained by a particular </span>river<span> and its tributaries is </span>called <span>either a </span>river<span> basin or </span>drainage<span> basin. </span>
Answer:
vancomycin
Explanation:
β-lactam antibiotics are those antibiotic that that contain a beta-lactam ring (the cyclic amide with the nitrogen atom attached to the β-carbon) in their molecular structures. This class of antibiotics is the most commonly used and it includes penicillin derivatives, cephalosporins, monobactams, and carbapenems. The mechanism of action of β-lactam antibiotics is inhibition of cell wall biosynthesis in the bacteria.
