1. Specialization and Stem cells

3. Why Specialize??
A single celled organism performs all required functions all in one cell.
Ex. An Amoeba

4. Why Specialize?? Multicellular organisms are much more complex.
Allocated cells , tissues and organs perform certain bodily functions.
Ex. Supply food and nutrients, transport materials, remove waste and fight infections

5. Specialized Cells
The structure matches the function!!

6. Stem Cell Stem cell: an unspecialized cell
Scientists study stem cells to learn more about specialization and differentiation
Stem cells can be used to treat injuries and diseases by regenerating organs
Stem cells can differentiate into any cell type of a plant or animal such as nerve, blood, or muscle cells of humans
Every cell in you body originally came from a small group of stem cells
These stem cells specialize when exposed to certain conditions such as hormones or can remain unspecialized and actively dividing for long periods of time

7. Animal Stem Cells Animal stem cells - two types
Embryonic stem cells can differentiate into other cell types
Adult stem cells are mature specialized cells mostly involved in replacement of damaged tissue

8. Plant Stem Cells Called meristematic cells
Found in growing tips of roots and stems
Meristematic cells in an onion root tip (magnification 25x)

9. Regeneration
Cell Regeneration: the process of replacing or regrowing a body tissue or organ
Salamanders - have unique ability to not only to regrow limbs that have been amputated but also tails, lenses in eyes, and parts of the heart.
Humans - the liver is the only organ that has the ability to naturally regenerate, and in young children, fingertips can also regenerate.

10. The axoloti is a type of salamander that can regrow amputated limbs
Regeneration of a newt’s limb over 6 to 8 weeks. The newt is a type of salamander.
The axoloti is a type of salamander that can regrow amputated limbs
videos.howstuffworks.com/science-channel/29246-kapow-superhero-science-limb-regeneration-video.htm?sort=most_watched&page=2

11. Current Research
Pig extracellular matrix applied to severed fingertip of human stimulates regrowth
Creation of body parts in the lab – success seen with:
Regrown bladder (picture)
Blood vessels
Heart valves
Image from:

12. Specialized Cells and Tissues
Its all about team work!
Tissue: groups of cells that function together to perform specialized tasks.

13. Animal Tissues 4 types of specialized tissues: Epithelial Tissue:
Lines body cavities and outer surface of body
Protects structures
Forms glands that produce hormones, enzymes and sweat
Connective Tissue:
Supports and protects structures
Forms blood
Stores fat
Fills empty space

14. Animal Tissues Muscle Tissue: Nervous Tissue: Allows for movement
Responds to stimuli
Transmits and stores information

15. Plant Tissues 4 types of specialized tissues Epidermal Tissue:
Forms the protective outer covering
Allows the exchange of materials and gases into and out of the plant through guard cell stomata
Vascular Tissue:
2 types of vascular tissue
Xylem: moves substances from roots to the leaves
Phloem: transports sugars from leaves to other areas

16. Plant Tissues Ground Tissue: Meristematic Tissue:
In the stem: provides strength and support
In the roots: stores food and water
In the leaves: photosynthesis
Meristematic Tissue:
Unspecialized tissue capable of dividing by mitosis
Found in several locations in the plant
Responsible for growing new parts of the plant

17. Plant Tissues