A vaccine uses a live pathogen that is too weak to make you sick. Once it enters your body you defeat it easily. Now that yur body is familiar with it your body can fight off the disease in the future.
Answer:
One key way by which species evolve over time in response to changes in environmental conditions is adaptation by natural selection acting over generations. Characteristics that aid in effective survival and reproduction in the new environment grow more prevalent, while those that do not become less prevalent.
Explanation:
The sun is about 109 times the size of earth, so about 0.073394495412844 inches wide:)
Answer: It is b multiple alleles
Explanation: Alleles determine your genes.
The answer is the first one The Earth rotates on its axis over 24hrs.