The toxicology lab examines the response of Tetrahymena cells to a variety of basic substances, looking at both lethal toxicity (LD50) and chronic sub-lethal toxicity. Students can use different concentrations of common substances suggested in the module (for example, shampoo, detergents, toothpaste, Windex) to determine lethal and sub-lethal dosage, or, under teacher supervision, design their own experiment to look at common substances of interest to them. The lab offers an opportunity for students at all levels to begin to address experimental design, the effect of experimental variables, and potential long term environmental impact of even commonly used items.

Module Protocols

High School

Glossary of Terms

Relevant Concepts

Science, Technology, and Society; Environmental Impact on Growth and Survival; Ecosystems and Relationships between Organisms

Next Generation Science Standards Relationships

High School:  |   |

Middle School:  | | |

NYS Science Curriculum Guideline Relationships

Key Ideas | | | | |


Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.
Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
Make and defend a claim based on evidence that inheritable genetic variations may result from: (1) new genetic combinations through meiosis, (2) viable errors occurring during replication, and/or (3) mutations caused by environmental factors.
Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species.
Create or revise a simulation to test a solution to mitigate adverse impacts of human activity on biodiversity.
Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.
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.
Construct a scientific explanation based on evidence for how environmental and genetic factors influence the growth of organisms.
Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
Construct an explanation based on evidence that describes how genetic variations of traits in a population increase some individuals’ probability of surviving and reproducing in a specific environment.
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.
Human decisions and activities have had a profound impact on the physical and living environment.