Question: Which sentence best describes the organization of the heart?
Choices:
The heart is an organ made up of different types of tissues, each of which has different types of cells.
The heart is a tissue made up of different types of organs, each of which has different types of cells.
The heart is a system made up of one type of tissue and identical cells.
The heart is a tissue made up of one type of organ and identical cells.
Answer: A