Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
The answer is B., Natural Selection.
Weather certainly doesn't change populations, and genes only caused individuals in a population to be slightly ( genetically-wise ) different from the others. It does cause change, but not change in the whole population over time.
Natural disasters don't change the populations over time either. Natural disasters only caused change in their environment, at most.
So, the only answer left is natural selection, and it makes sense too!
Natural selection is the process where the individuals with better traits suited to survive in that specific environment live on and give those good traits to their offspring.
The individuals with less suited traits to survive will die out, and will not be given an opportunity to reproduce and pass on their less suited traits, so over time, the population will increase of individuals with better suited traits to survive and the individuals with less suited traits will eventually die out, therefore making the entire population change.
Hope I helped you!
Answer:
it depends on changes in gene expression
Answer:
The answers are c)are the most reinforcing, generate the greatest immediate sensual appeal, and produce the most powerful psychological dependence.
Explanation:
Like all psychoactive substances, amphetamines affect the central nervous system and have stimulating effects (empathy, sensuality, confusion, etc.), producing an alert state along with various reactions in perception. Some individuals also report optical and auditory illusions. On many occasions this is also favored by the existence of intense visual and auditory stimuli, as happens for example at parties. However, most of these desired effects have tolerance with repeated doses of the same substances and even cross tolerance with doses of other substances. With the appearance of this tolerance other effects appear such as aggressiveness, anxiety symptoms, panic attacks, etc.
Among the medical complications related to the use of these substances, acute neurological complications, seizures and cerebrovascular diseases stand out.
Answer:
She should use the example of "the wave" in stadiums to illustrate the idea of a nerve impulse.
Explanation:
"The wave" in a sport stadium is a good example to explain how a nerve impulse works because it shows how an action potential travels from one point to its destination making changes in the membrane potential that would be the equivalent of people standing up and sitting down to allow the next row to do the same to reach its final destination.
