1. Levels of Organization
Chapter 3 Lesson 2
p.96-105

3. Organization of Unicellular
Organisms
Do unicellular organisms have all the
characteristics of life?
(i.e. respond to environment, get rid of waste, grow,
reproduce)

4. Prokaryotes
• Without a membrane
bound nucleus
• Smaller than eukaryotic
cells
• An organism the is a
prokaryotic cell is called
a prokaryote
• Some can live in
extreme environments

5. Eukaryotes
• Nucleus surrounded
by a membrane
• Specialized
organelles
• Eukaryotes

6. Multicellular Organisms
Organisms made up of many
eukaryotic cells working together.

7. Cell Differentiation
• In a multicellular organism there are many
types of cells.
• Each type of cell has a specific job, or
function

8. All multicellular organisms start
from one cell – a fertilized egg

9. Cell Differentiation

11. • By reading
different parts of a
chromosome, cells
become different
types.

12. Cell differentiation
• The process by which cells become
different types of cells

13. Animal Stem Cells
• Stem cell –
unspecialized
(undiffentiated)
cell that is able to
develop into
many cell types.

14. • Embryos have many more stem cells than
adult organisms.

15. • Adult organisms have some stem cells for
muscle repair and producing blood cells in
our bone marrow.

18. Plant Cells
• Stem cells in
plants are
called
unspecialized
cells
• They group in
areas called
meristems

20. • Cells in the meristem can become parts of
the stem, leaves, flowers, or roots.

21. Tissues

22. Plant Tissues

23. Organs
• Organs are groups of different tissues
working together to perform a particular
job.

24. Plant Organs
• Leaves are organs specialized for
photosynthesis.

26. Organ Systems
• Organ systems are
grouped of different
organs that work
together to complete
a series of tasks

27. Plant Organism Systems
• Two major organ systems:
– 1. shoot system
– 2. root system

28. Organisms
• Each organ system depends on the others and
cannot work alone.
• Muscle tissue could not work without blood from
the circulatory system.

29. Review
• All unicellular organisms carry out all the
activities necessary for survival within one
cell
• Cells become specialized in structure and
function during cell differentiation
• Organs are groups of different tissues that
work together to perform a job.

30. Homework
• Practice Book: p19-20
• Notebook:
– TB page 105
• #1-5