<span>The molecules that provoke a specific immune response are called antigens.
</span>This molecule initiates the production of an antibody and causes an immune response. T<span>oxins, chemicals, bacteria, viruses, or other substances that come from outside the body can be part of the antigens.
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Answer:
it exchanges oxygen and carbon dioxide
Explanation:
You inhale oxygen and exhale carbon dioxide
The answer is A because it is in order( idk how to explain but its A)
They are ectotherms.
hope it is helpful to you
Explanation:
energy flows in only one direction through an ecosystem.