Secondary sources draw on primary sources. They may comment on primary sources, or use the evidence from primary sources to construct an argument. Books or journal articles that analyze, critique, or synthesize a range of sources are examples of secondary sources.
At the end of Shakespeare's The Tragedy of Julius Caesar, Brutus comes to regret taking part in the murder of Caesar because he learns that the evidence concerning Caesar's attempts to usurp political power was, in fact, false. He realizes that if he hadn't been faced with this false evidence, then he would not have taken part in Caesar's murder.
Have you ever wondered what the inside of a cell looks like? If you think about the rooms in our homes, the inside of any animal or plant cell has many similar room-like structures called organelles. Each organelle is a place where specific jobs are done.
Plant and animal cells have many of the same organelles. But in some cases, the organelles in cells are different. For example, in plant cells, there are more types of organelles than are found in animal cells. Below are some names and descriptions of organelles commonly found in cells. There is also an interactive cell viewer and game that can be used to learn about the parts of animal and plant cells.