Most living organisms are single cells. Others, such as us, are like vast multicellular cities in which groups of cells perform specialized functions that are linked by intricate systems of intercellular communication. But even for the aggregate of more than 1013 cells that makes up a human body, the whole organism has been generated by cell divisions from a single cell. The single cell therefore contains all of the hereditary information that defines a species.
1.
Which word in the passage can be a clue to explain the word “aggregate”?
2.
The word “aggregate” in the passage is closest in meaning to? Use the clue.
