Answer:
In the first diagram the weakened pathogen (weaker version of the disease) is inserted into the bloodstream.
In the second diagram the antibodies kill the weakened pathogen. When the immune systems encounters a new disease it "remembers it".
This is why in the third diagram, when the "real" pathogen enters the bloodstream the immune system can effectively kill the disease. As the immune system "remembers" how to defeat the weakened version it can more effectively kill the "real" version.
Genetic variation is important because a population has a better chance of surviving and flourishing than a population with limited genetic variation. Genetic diversity also decreases the occurrence of unfavorable inherited traits.
Answer:
I think that the answer is c. If not then it is probably d or a.
Before the rise of the Mongols in the 13th century, it is now
called central and western Inner Mongolia, particularly the Hetao region,
change back and forth in control between Chinese agriculturalists in the south
and nomadic Mongol of the north. is known through Chinese chronicles and
historians.
My best answer would be the rising of sea levels would mostlikely be the outcome of increased global temperature.