Answer:
pollution from cars and factories.
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.
A classification system is a system with a distribution of classes created according to common relations.
Answer:
Taxonomy may be defined as the branch of biology that mainly deals with the classification, arrangement and nomenclature of the organism. Organism are classified into the different taxa depending on their similarities and differences.
The shared characters may be defined as the characters that are share among the two lineages. As given in the question, the two humps that are present on the bottom end of Pakicetus ankle bone is the shared distinguish character with the other ungulates that are even toed.
