1. Tissues

2. Tissues
Although all cells in your body contain the same DNA, they are not all alike. They have different functions and therefore different forms.

3. Tissues
Groups of cells that work together to perform the same function are called tissues.
In animals, the 4 types of tissues are:

4. Epithelial Tissue
Epithelial tissue is made of cells that are tightly packed together to form a protective barrier. It lines the outer surface of the body and body cavities.

5. Connective Tissue
Connective tissue joins and supports structures. It includes tendons, ligaments, bones, cartilage, blood, and fat.

6. Muscle Tissue
Muscle tissue includes both skeletal muscles that help you move and smooth and cardiac muscles that help your organs move.

7. Nervous Tissue
Nervous tissue responds to stimuli and sends signals through the body.

8. Plant Tissues
There are similarly 4 types of tissues in plants: vascular, (epi)dermal, ground, and meristematic.

9. Vascular Tissue Vascular tissue transports water and nutrients:
xylem moves water and minerals up from the roots; phloem moves the photosynthesized sugar around

10. (Epi)dermal Tissue
Epidermal tissue forms the protective outer covering and allows the exchange of materials (e.g. O2 and CO2) in and out of the plant (through stomata).
Section of a leaf:

11. Ground Tissue
Ground tissue provides support, stores water and nutrients, and is where photosynthesis happens (in the specialized mesophyll).
Section of a leaf:

12. Meristematic Tissue
Meristematic tissue (e.g. onion root tips) is where growth occurs.

13. Meristematic Tissue
The cells in meristematic tissue are stem cells: unspecialized cells that can become other specialized types of cells when exposed to special environmental conditions (differentiation).