Phagocytosis

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 mouth forms at certain temperatures in some mutants, or mutants with swimming defects that are unable to efficiently filter food from the water. The lab can also be used to address othe issues like pollution and toxicology, and can be combined with labs addressing the effects of cigarette smoke and alcohol.

Tetrahymena feeding

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

Phagocytosis video

(licensed under Creative Commons by-nc-nd 4.0)

 

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:  |

Middle School: | | |

Elementary School:  |

NYS Science Curriculum Guideline Relationships

Key Ideas | | | |

References

Use a model to illustrate that cellular respiration is a chemical process whereby the bonds of food molecules and oxygen molecules are broken and the bonds in new compounds are formed resulting in a net transfer of energy.
Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions.
Conduct an investigation to provide evidence that living things are made of cells, either one cell or many different numbers and types of cells.
Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function.
Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism.
Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
Use materials to design a solution to a human problem by mimicking how plants and/or animals use their external parts to help them survive, grow, and meet their needs.
Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.
Use a model to describe that animals’ receive different types of information through their senses, process the information in their brain, and respond to the information in different ways.
Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.
Use evidence to construct an explanation for how the variations in characteristics among individuals of the same species may provide advantages in surviving, finding mates, and reproducing.
The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing and creative process.
Beyond the use of reasoning and consensus, scientific inquiry involves the testing of proposed explanations.
The observations made while testing proposed explanations, when analyzed using conventional and invented methods, provide new insights into natural phenomena.
Organisms maintain a dynamic equilibrium that sustains life.
Plants and animals depend on each other and their physical environment.