The phagocytosis lab uses Tetrahymena to investigate the processes of ingestion, phagocytosis, and vacuole formation in cells, and the effects of various factors on these physiological processes. Students monitor vacuole development during feeding using digital cameras to record the data, learning microscopy and data collection and analysis as an integral part of the exercise. Students can look at feeding preferences, including live vs. dead food, big vs. small food, organic vs. inorganic material. The lab can be combined with a consideration of mutational effects by incorporating the use of mutants unable to eat for various reasons, e.g., mutants that fail to form mouths at certain temperatures, or mutants with swimming defects that are unable to efficiently filter food from the water. The lab can also be used to address other issues like pollution and toxicology, and can be combined with labs addressing the effects of cigarette smoke and alcohol.

Normal Tetrahymena feeding on ink particles. Each black spot is a separate food vacuole.

Phagocytosis video

Module Protocols

Elementary, Middle/High School

Relevant Concepts

Cellular Energetics; Chemistry of Life; Energy Transfer; Structural similarity between Single cell and Multicellular Organisms; Relationship of Structure to Function.

Next Generation Science Standards Relationships

High School: HS-LS1-7 | HS-LS2-3

Middle School: MS-LS1-1 | MS-LS1-2 | MS-LS1-7 | MS-LS2-3

Elementary School: 1-LS1-1 | 4-LS1-1 | 4-LS1-2 | 5-LS2-1 | 3-LS4-2

NYS Science Curriculum Guideline Relationships

Key Ideas 1.1 | 1.2 | 1.3 | 4.5 | 4.6