1. Structural Organization of Cells
7.L.3B.1 Develop and use models to explain how the structural organizations within multicellular organisms function to serve the needs of the organism.
Structural Organization of Cells

2. CELLS
TISSUES
ORGANS
SYSTEMS
Organism Hierarchy

3. The basic units of structure and function within all living things
The basic units of structure and function within all living things. Though all cells perform the processes that keep the organism alive, they also have specialized functions as well.
Examples may be nerve cells (neurons), blood cells, and bone cells, in animals and guard cells, xylem cells and phloem cells in plants.

4. A group of specialized cells that work together to perform a specific function.
Examples of the main types of tissue in animals are nervous tissue, connective tissue, muscle tissue, and epithelial tissue. Plants contain xylem and phloem tissue that is comprised of xylem and phloem cells.

5. A group of two or more different types of tissue that work together to perform a specific function. The task is generally more complex than that of the tissue.
For example, the heart is made of muscle and connective tissues which function to pump blood throughout an animal. Flowers, roots, and stems are organs in plants.

6. A group of two or more organs that work together to perform a specific function. Each organ system has its own function but the systems work together and depend on one another.
An example could be that plants and animals have a reproductive system.