Lesson plan
What’s the Glow About?
The purpose of this unit plan is to engage students in exploring the science of biofluorescence by examining its molecular and genetic foundations, comparing natural and artificial sources of glowing traits, and applying probability to inheritance patterns, while also considering ethical implications and ecological functions of fluorescence in living organisms.
Grades 9–12Biology & Life Sciences
Overview
Students study how organisms glow, distinguishing biofluorescence, bioluminescence, and general fluorescence. The lesson opens with video clips of biofluorescent organisms, a UV or blue light flashlight, and household fluorescent items, and students post questions on a question board. In lab stations they observe materials and GloFish under UV light, measure fluorescein and highlighter ink with a UV-Vis spectrophotometer, test glow sticks at different temperatures, and model electron excitation. They then link GFP to DNA, RNA, and protein, compare natural glow, GloFish, and dyes in a carousel, and complete a scenario-based assessment. Extensions cover GloFish Punnett squares and chi-square analysis. The plan gives one period for Engage, 2-3 periods for Explore, 2 for Explain, and 1-2 for Elaborate, plus a 30-minute assessment part in Evaluate.
Lesson Objectives
- Define and differentiate between biofluorescence, bioluminescence, and general fluorescence based on their light source, mechanism, and whether external light is required.
- Identify examples of organisms and materials that exhibit these various forms of light production.
- Explain the molecular basis of biofluorescence, specifically the role of genetically encoded fluorescent proteins (like GFP) in absorbing and re-emitting light at different wavelengths.
- Describe the genetic pathway (Central Dogma) from DNA to RNA to fluorescent protein, demonstrating how biofluorescence is an inherited trait.
- Compare and contrast natural biofluorescence with artificially induced glowing (e.g., dyed organisms, genetically engineered GloFish), emphasizing the heritability and permanence of the trait.
- Analyze the ethical considerations surrounding genetically modified organisms, particularly in the context of commercial applications like GloFish.
- Apply probability concepts (e.g., sample space, Punnett squares, theoretical vs. empirical probability) to predict and analyze the inheritance patterns of the fluorescent trait in organisms like GloFish.
- Discuss the ecological roles and potential evolutionary advantages of biofluorescence in various organisms.
- Describe methods used to study biofluorescence in organisms (e.g., UV-Vis spectroscopy, observation under UV light).
Standards
NGSS · 9
- HS-LS1-1Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions of life through systems of specialized cells.
- HS-LS1-2Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.
- HS-LS1-3Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.
- HS-LS4-1Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.
- HS-LS4-2Construct an explanation based on evidence that the process of evolution primarily results from four factors: (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.
- HS-LS4-3Apply concepts of statistics and probability to support explanations that organisms with an advantageous heritable trait tend to increase in proportion to organisms lacking this trait.
- HS-LS4-4Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
- HS-LS4-5Evaluate 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.
- HS-PS1-2Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.
CCSS Math · 3
- MP1Make sense of problems and persevere in solving them: Students will need to interpret information about bioluminescence and fluorescence, analyze data, and solve problems related to genetic probabilities.
- HSS-CP.A.1Describe events as subsets of a sample space (the set of all possible outcomes) using characteristics (or categories) of the outcomes, or as unions, intersections, or complements of other events ("or," "and," "not"). Application: Offspring of a dye injected glo fish with a natural glo fish, what is the outcome?
- HSS-CP.A.4Construct and interpret two-way frequency tables of data when two categories are associated with each object being classified. Use the two-way table as a sample space to decide if events are independent and to approximate conditional probabilities.
CCSS ELA · 9
- RST.6-8.1Cite specific textual evidence to support analysis of science and technical texts. Application: Students will read articles/websites about bioluminescence, fluorescence, and GloFish genetics. They should be able to identify and quote specific sentences or phrases that answer questions about these topics. (e.g., "According to the article, bioluminescence occurs when...")
- RST.6-8.2Determine the central ideas or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinions. Application: Students will summarize the key differences between bioluminescence and fluorescence, or the main points about how GloFish are genetically modified.
- RST.6-8.3Follow precisely a multi-step procedure when carrying out experiments, taking measurements, or performing technical tasks. Application: When conducting the "Explore" activities with glow sticks, black lights, and fluorescent materials, students will follow step-by-step instructions.
- RST.6-8.4Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context. Application: Students will learn and use vocabulary such as "bioluminescence," "fluorescence," "genetics," "GMO," "DNA," "gene," "protein," "phenotype," "genotype," "allele," "dominant," "recessive."
- RST.6-8.5Analyze the structure an author uses to organize a text, including how the major sections contribute to the whole and to an understanding of the topic. Application: Students might analyze how a scientific article about GloFish is structured (e.g., introduction to the fish, explanation of the modification process, ethical considerations).
- RST.6-8.6Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text. Application: Students can discuss why a certain website or article presents information about GloFish the way it does (e.g., is it promoting GloFish, warning about them, or just explaining the science?).
- RST.6-8.7Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table). Application: This is crucial for the genetics component. Students will interpret diagrams of DNA and genes, and use Punnett squares (a visual/mathematical representation) to understand genetic crosses. They should be able to explain the information from these visuals in words.
- RST.6-8.8Distinguish among facts, reasoned judgment based on research findings, and speculation in a text. Application: Especially when discussing the ethics of GMOs or the potential impact of GloFish, students will need to differentiate between scientifically proven facts, expert opinions, and unsubstantiated claims.
- RST.6-8.9Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic. Application: Students will compare their observations of real GloFish (or videos) with what they read about their genetics and glowing properties. They will compare information from different sources (e.g., a scientific journal article vs. a news report about GMOs).