Rewriting Survival: Genetics and the Future of Coral Reefs
Investigate coral bleaching through hands-on experimental design, data analysis, and a bioethical debate on using CRISPR for conservation.
Climate change is the biggest threat to coral reefs. Can we use modern genetic tools as one method to help us understand coral biology and perhaps make corals more adaptive to climate change?
NGSS:
- HS-LS2-7: Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
- HS-LS2-2: Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.
- HS-LS4-2: Construct 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-LS4-4: Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
- HS-LS4-5: Evaluate evidence supporting claims that changes in environmental conditions may result in increases in some species, emergence of new species, and extinction of other species.
- HS-LS2-6: Evaluate claims, evidence, and reasoning that ecosystem interactions maintain relatively consistent numbers and types of organisms, but changing conditions may result in a new ecosystem.
- HS-ETS1-3: Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs.
This is a 3-day lesson plan consisting of:
- Day 1 - Corals: On the Brink Video and Corals 101 Stations (60 minutes)
- Day 2 - Surviving the Shift: Coral Adaptation Lab Challenge (50 minutes)
- Day 3 - Using CRISPR to Save Corals? (50 minutes)
Subject Areas: Honors Biology, CP Biology
Prior Knowledge: Students need a foundation in several key biology concepts to successfully engage with this lesson. They should understand the basics of photosynthesis and cellular respiration, including how energy is captured and transferred in living systems. This is especially important for understanding the relationship between corals and their symbiotic algae. Students should also have a basic understanding of molecular genetics, including the relationship between DNA, RNA, and proteins, and how genes are expressed to produce traits. This background helps them make sense of how changes to a gene (such as through CRISPR) can impact an organism’s phenotype. In addition, students should be familiar with the process of natural selection, with a particular emphasis on genetic variation within populations. They should understand that variation in traits can influence survival and reproduction, which is critical for connecting the idea of heat tolerance in corals to both natural selection and potential genetic modification. Students should be familiar with basic concepts of experimental design, including independent variables, dependent variables, control groups, and constants.
Learning Objectives:
- Explain how coral functions as a keystone species and predict how changes to coral populations impact entire reef ecosystems.
- Analyze the impact of climate change on ocean systems, including how rising temperatures lead to coral bleaching and affect biodiversity.
- Explain how genetic variation can influence coral survival in response to rising ocean temperatures.
- Using gene editing in conservation may help species survive climate change, but potential ecological risks and ethical issues should be considered.
Materials Needed:
- Projector & computer with internet access to play videos in Days 1 and 3
- Student worksheets, depending on which activities are selected for Days 1, 2, and 3
- Corals 101 Stations Materials for Day 1
- Large Poster Paper or Whiteboards for Day 2
- Experimental Supply Cards for Day 2 (one set per group)
- Experimental Results (one set per group) for Day 2
- Gene Editing Scenario cards for Day 3 (one set per group)
Lesson Activities: Login to Download Lesson
Warm-up and Video Viewing (15 minutes)
Give students two minutes to quickly write down anything they know about coral reefs. Prompting questions include:
- What are coral reefs made of?
- Where are they found?
- What lives there?
- Why might coral reefs matter?
- How could climate change affect them?
- How could we save or protect coral reefs?
Next, have students circle one idea they are most confident about and one they are most unsure about. Ask students to add one fact and one question they have to their list while they watch the film Corals: On the Brink.
Introduce Dr. Line Bay. She is the narrator of the SCL video Corals: On the Brink and the researcher whose work on coral reefs inspired the activities in this lesson.
Show students the video, Corals: On the Brink (10 minutes 31 seconds).
Corals 101 Stations (45 minutes)
In this activity, students in groups of 2-4 rotate through 3 stations to learn about corals as organisms and the role of corals as a keystone species. Students complete the Corals 101 Student Worksheet using the materials provided at each station.
The rotation through the Corals 101 Stations takes approximately 15 minutes per station. This is set up as a 3 stations activity (see materials and instructions listed below). I created duplicates of the 3 stations to accommodate larger classes.
Materials for each station:
Station 1: Corals as a Keystone Species
- Print the Coral Reef Species Cards.
Station 2: Coral Symbiosis at the Cellular Level
- Mutualism, Commensalism, and Parasitism Information Card
- NOAA Coral Bleaching Poster
- Coral Symbiosis Reading: Coral Reef: A Partnership for Survival
Station 3: Coral Reproduction
- Sexual or Asexual Reproduction Cards
- Coral Sexual vs. Asexual Reproduction Reading
- Colored Pencils/Markers for graphing
Reviewing the environmental issues coral reefs face (5 minutes)
Have students answer questions in Part 1 of the Surviving the Shift: Coral Adaptation Lab Challenge Worksheet. Students should use their knowledge from the Corals 101 Stations to answer questions 1-2. Depending on the level of chemistry and background knowledge, students may need help answering question 3 about ocean acidification.
To review these concepts, students can watch the following optional videos: Science Today: Ocean Acidification and The Carbon Cycle.
Lab Challenge (30 minutes)
Divide students into groups of 3–4.
Introduce the concept of a mesocosm: a human-made ecosystem designed for scientific research that includes all the components of a natural ecosystem, but on a reduced scale. Researchers use mesocosms to study a variety of ecological processes, including the impacts of climate change and environmental interactions. They can range from small terrariums to larger systems like water tanks, and may be classified as either closed or open systems.
For this lab, challenge students to design an experiment to test the impacts of chronic 2 °C ocean warming and acidification conditions expected later this century under the Paris Climate Agreement. Provide students with an envelope with the Experiment Supply Pictures. Inform students that they have four mesocosms available for their experiment, along with the supplies in the envelope provided.
Allow about five minutes for groups to brainstorm and answer Part 2, question 1 before they begin creating their experimental design posters. Students should use only the materials in the envelope (unless you choose to allow additional supplies—my students had to petition the project manager if they needed more) and may use up to four mesocosms. They do not need to use all of the materials provided. Students should answer questions 2-5 and create a poster that showcases the experiment they designed.
Optional: Gallery Walk (10 minutes)
If time permits, have students complete a gallery walk to observe other groups' experimental designs. During this time, students can ask questions to one another about their ideas and the reasoning behind each other's designs, allowing students to compare and contrast their designs.
Literature Review and Interpretation (25 minutes)
Next, provide students with the Physiological Acclimatization in Hawaiian Corals Student Handout, which presents results from an authentic experiment. Students should analyze the data by completing Part 3, questions 1–3, then compare their original experimental design to the methods used in the study. As a final formative assessment, students reflect on how they would revise and improve their own design based on evidence from the paper (questions 4-5).
Note: Physiological Acclimatization in Hawaiian Corals Student Handout could be modified depending on the level of your students. I used Figure 6 in page 3 as with my most advanced students.
Materials needed (Day 2):
- Surviving the Shift: Coral Adaptation Lab Challenge Student Worksheet
- Poster Paper (one per group)
- Markers
- Experiment Supply Pictures (one set per group; Cut out and put in envelopes)
- Color copies of the Physiological Acclimatization in Hawaiian Corals Student Handout (one per group)
This part introduces students to the concept of gene editing and CRISPR and incorporates the SCL film The Century of Biology. If students aren’t familiar with gene editing and CRISPR, you could briefly introduce the concepts in a short presentation before starting this section.
Video Viewing (10 minutes)
Begin the lesson by showing the SCL film The Century of Biology. As they watch the film, have students record answers to questions in Part 1 from the Using CRISPR to Save Corals Student Worksheet.
Gene Editing Decision Cards (15 minutes)
Divide students into groups of 2–3 and give each group a set of gene editing decision cards. Students should sort the cards according to the instructions on the student worksheet. They should record their responses in the chart and answer questions 2–4 of Part 2 with their group. Have groups share their responses with the class.
Literature Review and Interpretation (25 minutes)
Next, tell students they will read a summary of a research study designed to identify genes that influence coral’s ability to withstand higher temperatures. If students completed the experimental design challenge in Part 2, remind them that different genes showed varying abilities to withstand the different conditions in the mesocosms.
Students should read the research summary and answer questions 1–6 from Part 3. Consider using these questions as a formative assessment to check for student understanding.
Materials needed (Day 3):
- SCL Film: The Century of Biology
- Using CRISPR to Save Corals Student Worksheet
- Gene Editing Decision Cards (one set of cut cards per group)
In Day 3, more advanced students who already understand the concept of gene editing could view the whiteboard animation CRISPR: A Word Processor for Editing the Genome and use Option B of the Using CRISPR to Save Corals Student Worksheet. This version focuses more on the mechanism by which CRISPR-Cas9 edits the genome
As an extension to Day 3, consider using the lesson, “Engineering the World Around Us: Genome Editing and the Environment” from Personal Genetics Education & Dialogue (PRED). The lesson focuses on how gene editing could potentially improve human health, agriculture, and the environment.
More Info:
- For larger classes, it is recommended to have multiple copies of each station for the Corals 101 Activity.
- Groups of four students work well for the coral experimental design challenge activity.
- Consider guiding lower-level classes or classes that have not had as much data interpretation practice through the data analysis portion of the lab challenge.
What Worked Well:
- The story-driven hook with Corals: On the Brink engaged students immediately because it humanizes the science and gives them a clear sense of purpose. The visuals and real-world stakes, including reef loss and climate change, made the content feel relevant even before students fully understood the biology. This led to stronger investment in the more complex genetics and ecology that followed.
- The experimental design challenge required students to design their own investigation around warming and acidification conditions, which pushed them into authentic scientific thinking. The limitations, such as restricted materials and a set number of mesocosms, made the task feel realistic and required problem-solving rather than simple recall. This activity also allowed for real-time assessment of student understanding of experimental design and provided opportunities to challenge and refine their thinking.
- Having students analyze the Hawaiian coral study and compare it to their own design helped them recognize what authentic experimental design looks like and pushed them to improve their thinking. The reflection component, which focused on how they would revise their design, strengthened their understanding of variables, controls, and long-term data collection. Student engagement was high because the data felt meaningful and directly connected to their own work.
- Day 1: Corals 101 Stations — Answers to the Corals 101 questions demonstrate student understanding.
- Day 2: Coral Adaptation Lab Challenge — Application questions ask students to justify design choices and predict outcomes.
- Day 2: Coral Adaptation Lab Challenge — Reflection prompts ask students to compare their design to a real research study, focusing on how they would improve it.
- Day 2: Coral Adaptation Lab Challenge — Group lab posters demonstrate understanding of experimental design.
- Day 3: Using CRISPR to Save Corals? — Analysis questions show student understanding of using CRISPR to create knockout organisms and determine gene function.
What My Students Learned:
- Students developed a deeper understanding of biology by connecting genetics, ecology, and climate change.
- Students improved their ability to use data and evidence to support explanations and justify ideas.
- Students saw themselves as capable of reading scientific literature and engaging in real-world conservation issues.
- P. A. Cleves, A. I. Tinoco, J. Bradford, D. Perrin, L. K. Bay, J. R. Pringle, Reduced thermal tolerance in a coral carrying CRISPR-induced mutations in the gene for a heat-shock transcription factor (2020)
- Van Oppen M.J., Oakeshott J.G., A breakthrough in understanding the molecular basis of coral heat tolerance. (2020)
- iBiology/Youreka Science: CRISPR: A Word Processor for Editing the Genome
- McLachlan, R.H., Price, J.T., Muñoz-Garcia, A. et al. Physiological acclimatization in Hawaiian corals following a 22-month shift in baseline seawater temperature and pH. Sci Rep 12, 3712 (2022).
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Lesson Plan by
Jennifer Broo
Mariemont High School
