Cells

1. Animal

1.1. differntiated

1.1.1. Nerve cell

1.1.2. Sperm cell

1.1.3. Red blood cell

1.1.4. Egg cell

1.1.5. Muscle cell

1.2. undifferniated

1.2.1. Stem cells

1.2.2. Stock standard cell

2. plant

2.1. differentiated

2.1.1. Root hair cell

2.1.2. Xylem cell

2.1.3. Phloem cell

2.2. undifferntiated

2.2.1. Stock standard plant cell

2.2.2. Stem cells

3. Tissues

4. Organs

5. Organ systems