Georgia Performance Standards

1

2.4 Stem Cells Cell Specialization

• Georgia Performance Standards
• Analyze the relationship between single
  (unicellular) and multi-celled organisms and the
  increasing complexity of systems.

• Essential Question
• How are cells categorized?

2
Warm-up

• 1. Some activities cannot be performed by only
  one person, but need a team of people. What type
  of activity requires a team of people to work
  together in order to complete a task?
• 2. What do you think are some characteristics of
  a successful team?
• 3. How is a multicellular organism similar to a
  successful team?

3
 The Diversity of Cellular Life 

• What is cell specialization?
• All cells, no matter how different they may seem,
  use the same basic chemistry.
• This does not mean that all living things are the
  same.
• Cells are specialized to perform certain tasks,
  either as individuals or as parts of larger
  organisms.

4
Unicellular Organisms

• A single-celled organism is also called a
  unicellular organism.
• Unicellular organisms do everything that you
  would expect a living thing to do.
• They grow, respond to the environment, and
  reproduce.

5
A Unicellular Organism
The spiral-shaped bacterium Leptospira
interrogans is a unicellular organism that causes
a serious disease in humans (magnification
27,000).
6
Unicellular organisms Include both Prokaryotes
Eukaryotes

• Many eukaryotes also spend their lives as single
  cells.
• Some types of algae, which contain chloroplasts
  and are found in oceans, lakes, and streams
  around the world, are single-celled.
• Yeasts, or unicellular fungi, are also
  widespread.

• Prokaryotes (bacteria) are very adaptable.
• Bacteria live almost everywherein the soil, on
  leaves, in the ocean, in the air, and even within
  the human body.

7
Colonial Organisms

• Some species of protists and algae are colonial.
• Colonial organisms
• live in groups of individuals of the same species
• are attached to one another but have few
  specialized structures.

8
Multicellular Organisms

• The cells of multicellular organisms, such as
  human beings, do not live on their own. They are
  interdependent
• Organisms that are made up of many cells that
  work together are called multicellular organisms.
  
• Multicellular organisms have cell specialization,
  or separate roles for each type of cell.    
• Cells in multicellular organisms are specialized
  to perform particular functions within the
  organism.

9
What are the four levels of organization in
multicellular organisms?

• The levels of organization in a multicellular
  organism are
• individual cells
• Tissues
• Organs
• organ systems.

10
(No Transcript)
11
Cells 

• The organization of the cells of the body creates
  a division of labor among those cells that makes
  multicellular life possible.
• This specialization and interdependence is one of
  the remarkable attributes of living things.

12
Tissues 

• A tissue is a group of similar cells that perform
  a particular function.
• Most animals, which are multicellular organisms,
  have four main types of tissue
• Muscle
• Epithelial skin
• Nervous
• connective tissue bone, blood, cartilage, and
  lymph.

13
Organs 

• Many tasks within the body are too complicated to
  be carried out by just one type of tissue.
• In these cases, many groups of tissues work
  together as an organ.
• For example, each muscle in your body is an
  individual organ.
• Within a muscle, however, there is much more than
  muscle tissue.
• There is nerve tissue, and there is connective
  tissue, which connects different parts of the
  body.
• Each tissue performs an essential task to help
  the organ function.

14
Organ Systems

•  A group of organs that work together to perform
  a specific function is called an organ system.
• There are 11 major organ systems in the human
  body.

15
Levels of Organization
Muscle cell
Smooth muscle tissue
Stomach
Digestive system
Go to Section
16
Cell DIFFERENTIATION
17
Checkpoint Questions

• In what kinds of organisms is cell specialization
  a characteristic?
• List the levels of biological organization from
  most simple to most complex.
• 3. Which level of organization is represented by
  the eye?
• 4. Give two examples of an organ system.
• 5. Muscle cells have a large number of which
  organelle?

18
Cellular Reproduction
Chapter 9
9.3 Cell Cycle Regulation
Stem Cells

• Unspecialized cells that can develop into
  specialized cells when under the right conditions

19
Cellular Reproduction
Chapter 9
Embryonic Stem Cells

• After fertilization, the resulting mass of cells
  divides repeatedly until there are about
  100150 cells. These cells have not become
  specialized.

20
Cellular Reproduction
Chapter 9
Adult Stem Cells

• Found in various tissues in the body and might be
  used to maintain and repair the same kind of
  tissue

• Less controversial because the adult stem cells
  can be obtained with the consent of their donor

21
Stem Cell Movie

• http//learn.genetics.utah.edu/content/tech/stemce
  lls/sctypes/