Because an antibody is "made" relative to the antigen, but kept at low levels when you are exposed the first time ("primary immune response"). The second time you're exposed to the same antigen, memory cells recognize it and the body produces a high level of antibodies, and the level of antibodies usually remains higher for a longer time ("secondary immune response"). This is your basic immune response (primary and secondary).
This explains exactly why vaccines are effective to extremely effective.
<span>Answer: a) a series of anatomical traits that distinguish Cro-magnon features from Neandertals.</span>
<span>Neanderthals (Homo neanderthalensis) were first discovered in Germany in 1856 and are believed to emerged between 100,000 and 200,000 years ago. </span>
<span>Significant differences found in the human and </span>Neanderthal includes<span>: 1) their DNA, 2) the brain of a Neanderthal had a raised larynx and was also bigger, and 3) Compared to modern humans, Neanderthals had bigger and muscular body but with shorter legs.</span>
Cro-magnon is<span> the earliest known Western European example of our species who lived 35,000 and 10,000 years ago. They are believed to be actually modern in every anatomical respect. They are much like us.</span>
<span>Neanderthal and Cro-magnon were believed to overlap in Europe for a thousand years but long-term interbreeding was not seen. </span>
DNA analysis helps scientists classify similar animals by the evidence of relatedness in general the more derived genetic characters to organisms share the more closely repeated they are...In other words “DNA helps scientists by comparing the similarities in each animal/person’s DNA.
Answer:
Natural selection acts on <u>individuals </u>which may result in the evolution of <u>populations.</u>
Explanation:
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