The document outlines the different levels of biological organization from the broadest to the most specific. It begins with the biosphere as the entire planet and ecosystems as living things in a particular region and their environment. Within ecosystems are communities as the living parts and populations as groups of the same type of organisms that interbreed. Organisms are independent individuals and cells are the simplest entities with the properties of life. The levels can be grouped into cellular, organismal, and populational categories.

1. Levels of Biological Organization

2. Biosphere
Our entire planet Earth and all its living
inhabitants.

3. Ecosystem
Living things in a particular region and their
nonliving physical environment.

4. Community
• The living part of an ecosystem.

5. Population
• Group of individuals of a particular type that
live in the same area and actively interbreed
with one another.

6. Organism
• Independent individual.

7. Organ system
• Body part arranged to carry out a particular
general function within the organism.

8. Organ
• Group of tissues that perform specialized
function.

9. Tissue
• Group of similar cells.

10. Cell
• The simplest entity that has all the properties
of life.

11. Organelle
• Structure that performs specialized function
for the cell.

12. Molecule
• Clusters of atoms.

13. Atom
• The smallest unit of matter that still has
distinct chemical properties.

14. Subatomic particles
• Fundamental units of energy and matter.

15. All levels can be grouped in 3:
• Cellular
• Organismal
• Populational

19. Review
• Clusters of atoms. (molecules)
• Our entire planet earth. ( ? )
• Independent individual. ( ? )
• Group of similar cells. ( ? )
• All of the various species living in the same
area. ( ? )
• Structure that performs specialized function
for the cell. ( ? )

20. Question 1
• Which of the following is defined as “the
living part of an ecosystem?”
• A. biosphere.
• B. community.
• C. organism.
• D. population.
• E. ecosystem.

21. Question 2
• Which of the following is defined as “group
of individuals of a particular type that live in
the same area and actively interbreed with
one another?”
• A. ecosystem.
• B. community.
• C. population.
• D. organism.

22. Answers
Question 1: B. community.
Question 2: C. population.