Answer:
While exercise is a common cause of muscle fatigue, this symptom can be the result of other health conditions, too.
Causes of muscle fatigue
Addison's disease.
age.
anaerobic infections.
anemia.
anxiety.
botulism.
cerebral palsy.
chemotherapy.
Answer:
Natural selection can be described as a phenomenon in which individuals of a population which are better adapted to survive in an environment are favored by nature as compared to the individuals of the population which lack better characteristics to survive in the environment.
Through natural selection, evolution occurs and the allelic frequency changes over a period of time. The process of evolution as well as change in the allelic frequencies does not occur just by a single individual, rather it is a collective effort which takes a lot of time. Hence, we say that natural selection changes the population and not a single individual.
<span>Chlorofluorocarbons
(CFCs) chemicals contain carbon, chlorine and fluorine and is t so expensive at
the same time it’s not flammable, the reason why it is mainly used in business
such as refrigerators and plastics. However, these chemicals destroys our
stratosphere, the second layer of the Earth’s atmosphere and protects us by
blocking the ultraviolet radiation (UV Light). This type of radiation can seep
through organisms skins and can leave destructive effects on DNA molecules
which will also cause skin cancer.</span>
