1. Hmdscience.com username: cpiro23 password: x2p4n 

2. Student Learning Objective:
Describe cell specialization and levels of organization and identify how levels
of organization work together in an organism.
Essential Question: What job does a structure do, and how does it do it?

3. Key Terms determination differentiation tissue organ organ system
Mountain climbing requires careful interaction among all parts of the human body; the brain and muscles have to work together to coordinate a climber’s movements. In addition, the heart and lungs also have to work together to help provide energy for the climb. How do such different parts coordinate their activities to keep the body functioning?
Key Terms
determination
differentiation
tissue
organ
organ system

4. Zygotes first divide into embryonic stem cells.
Stem cells develop in two stages.
determination, or committing to become one cell type
differentiation, or acquiring specialized structures and functions

5. Specialized cells develop from a single zygote.
Organisms are made up of specialized cells.
red blood cell
nerve cell

6. What are some of the reasons that multicellular organisms need specialized cells?
Multicellular organisms need specialized cells to build specialized tissues and organs that carry out functions such as respiration, digestion, and elimination. Specialization also allows multicellular species to become much larger than unicellular species can.

7. Specialized cells perform specific tasks.
Specialized cells function together in tissues, organs, organ systems, and the whole organism.
Specialized cells perform specific tasks.
Tissues are groups of similar cells working together.
epithelial tissue
connective tissue
muscle tissue
nervous tissue
cell
tissue

8. Tissues are composed of one specific type of differentiated cell.
Organs are different tissues working together.
Organ systems are two or more organs working together.
Organism is all organ systems working together.
ORGANS
ORGAN SYSTEM
ORGANISM

9. There are 11 major organ systems in the human body.

10. 1. How does the process of cell determination differ from the process of cell differentiation? 2. Briefly define each of the five levels of organization in multicellular organisms. (Bonus: give an example of each level)
3. Which cells are produced during the first few
divisions of the zygote?
a. epithelial cells b. cardiac muscle cells c. bone cells d. embryonic stem cells

11. In cell determination, stem cells commit to becoming a certain type of cell, such as a muscle cell. In cell differentiation, cells develop the actual structures and functions that make them specialized cells.
2. A cell is the smallest unit of life (example:neuron). A tissue is a group of similar cells that work together to perform a specialized function (example: nerve tissue). Organs consist of two or more types of tissues that function together (example: brain). Organ systems consist of two or more organs working together (example: brain and spinal cord).
3. d. embryonic stem cells