Question

the circulatory system
select the true statement.
cells, tissues, and organs all work together to make up organ systems.
the smallest and simplest systems within organ systems are the organs.
organ systems work independently from the rest of the body.

Explanation:

In biological organization, cells form tissues, tissues form organs, and organs work together to form organ - systems. Organs are not the smallest in organ - systems (cells and tissues are smaller). Also, organ systems do not work independently but interact with other systems in the body.

Answer:

Cells, tissues, and organs all work together to make up organ systems.