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.
Answer:
That's correct im pretty sure
Explanation:
Because you are adding a nucleotide which is a frameshift mutation.
Good job for getting the answer
Answer:b
Explanation:some seeds do not germinate during adverse conditions.this is called dormancy.this may occur due to hard seed coat.this seed coat prevents the entry of water and oxygen which are necessary for the plant to grow and germinate.
Water is a nessesary medium for essential metabolic reactions in the seed.the temperature at which is seed would germinate also varies.
Oxygen is needed for a germinating plant to obtain energy through respiration. The seed coat may also be so tough that they resist growth and expansion from taking place.
Seeds are able to break dormancy on their own.some may need to undergo natural processes that lead to softening.this process may be slow.some others may need heat or certain nutrients.
Germination of seed occurs when the dormant plant has taken in water and oxygen to show high metabolic activities leading to the formation of a seedling.
The are coded in the arrangement of either chromosones or DNA.
