Learning Outcomes:
i. Students will describe the structure and function of cilia and flagella.
ii. They will understand the differences and similarities between cilia and flagella.
iii. Students will recognize the role of these structures in cell movement and other cellular functions.
Summary of Lesson:
Cilia and flagella are like the oars and propellers of a cell, helping it move and navigate through its environment. This lesson introduces these tiny yet powerful structures, explaining how they work and why they're so important for the cells that have them.
Content:
i. The Dynamic Duo: Cilia and Flagella: Cilia and flagella are hair-like structures that extend from the surface of many cells. They are composed of microtubules arranged in a '9+2' structure, all enveloped by the cell membrane.
ii. Cilia: The Oars of the Cell: Cilia are short, numerous, and often cover the entire surface of the cell membrane. They move in coordinated waves, like oars on a rowboat, to move the cell or to move fluids across the cell's surface.
iii. Flagella: The Propellers of the Cell: Flagella are longer and usually number just one or a few per cell. They have a whip-like motion that propels the cell forward, much like a boat's propeller.
iv. Functions Beyond Movement: Besides locomotion, cilia have additional roles, such as moving mucus in the respiratory tract and helping with the cell's sensory functions. Flagella also contribute to sensation in certain cells.
List of Important Questions for Self-Study:
i. What are cilia and flagella, and how are they structurally similar?
ii. How do the movements of cilia and flagella differ?
iii. Why are cilia and flagella important for single-celled organisms?
iv. What roles do cilia play in human health?
v. How does the arrangement of microtubules contribute to the function of cilia and flagella?
vi. In what ways can defects in cilia or flagella affect a cell or an organism?
vii. How do cilia and flagella contribute to the survival and adaptation of organisms in different environments?
viii. Why might a cell need to have both cilia and flagella?
ix. How do cilia and flagella demonstrate the concept of structure-function relationship in biology?
x. Can you identify an organism that uses flagella for movement?
Important Terminologies Used in Lesson:
i. Cilia: Microscopic, hair-like structures on the surface of cells that beat in coordinated patterns to facilitate movement or fluid flow.
ii. Flagella: Longer, whip-like structures that help in cell motility and are often fewer in number compared to cilia.
iii. Microtubules: Cylindrical structures that are part of the cytoskeleton, made of protein tubulin, which make up the core of cilia and flagella.
iv. '9+2' Structure: The arrangement of microtubules in cilia and flagella, with nine pairs of microtubules surrounding two central microtubules.
v. Locomotion: The ability of an organism or cell to move independently using metabolic energy.
