Students use classic experiments to explain how DNA was identified as the genetic material.
This digital biology lesson guides students through the major experiments that demonstrated DNA is the molecule of heredity and led to the discovery of its structure. Students analyze historical data using Claim–Evidence–Reasoning (CER) to understand how scientists built and tested genetic theory over time.
Rather than memorizing names and dates, students work directly with experimental logic and results to determine how each study contributed to modern genetics.
Students examine four foundational experiments:
• Griffith (1928) — transformation in bacteria
• Avery, MacLeod, and McCarty (1944) — identification of DNA as the transforming factor
• Hershey and Chase (1952) — confirmation that DNA, not protein, is genetic material
• Chargaff (1949) — base-pairing relationships in DNA
For each experiment, students:
• analyze data or diagrams
• determine the claim supported by the results
• cite evidence
• justify conclusions using structured reasoning
Each investigation includes differentiated scaffolding options, allowing students to work:
• independently
• with claim hints
• or with visual guidance
Students then explore the discovery of DNA’s structure and the contributions of:
• Watson
• Crick
• Wilkins
• Rosalind Franklin
They evaluate how evidence supported the double helix model and reflect on how credit was distributed among scientists.
• DNA as genetic material
• Experimental design and interpretation
• Transformation
• Protein vs. DNA evidence
• Base-pair relationships
• Scientific reasoning (CER)
• History of science
• Builds deep conceptual understanding of genetics
• Shows how evidence changes scientific models
• Supports CER and argumentation
• Includes built-in differentiation
• Integrates science history with data analysis
• Works for guided instruction or independent work
• Minimal prep required
This resource is a digital interactive lesson (Google Slides compatible).
Includes:
✔ Student analysis slides
✔ Differentiated support options
✔ CER writing prompts
✔ Teacher answer key
✔ Exit ticket
• High school biology
• Genetics and heredity units
• History of science instruction
• CER skill development
• Inquiry-based learning
• Digital or hybrid classrooms
Grade & Course Recommendation:
Middle School:Grade 8 honors life science, during heredity or molecule of life units.
High School:Grade 9–11 Biology, as an introduction to molecular genetics.
To preview this lesson, click here.
Cross-Curricular Connections:
History of Science: Connects to the scientific process through the discovery timeline (Griffith, Avery, Hershey–Chase, Watson & Crick).
ELA Integration: Students summarize historical readings and defend evidence-based claims about scientific breakthroughs.
Art Integration: Creation of DNA structure models reinforces spatial understanding.
HS-LS1-1: Construct 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. (connection: understanding how DNA’s structure was discovered and why it is central to heredity)
HS-LS3-1: Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring. (connection: exploring historical experiments that established DNA as the molecule of inheritance)
HS-LS3-2: Make and defend a claim based on evidence that inheritable genetic variations may result from new genetic combinations through meiosis, errors during replication, and/or mutations caused by environmental factors. (connection: understanding DNA’s role in heredity and variation)
Science & Engineering Practices: Analyzing and interpreting data; Constructing explanations; Engaging in argument from evidence.
Crosscutting Concepts: Structure and function; Cause and effect; Systems and system models.
CCSS.ELA-LITERACY.RST.9-10.1 / RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts. (connection: reading passages on Franklin, Watson, and Crick to analyze scientific reasoning and ethics)
CCSS.ELA-LITERACY.RST.9-10.4 / RST.11-12.4: Determine the meaning of key scientific terms and phrases as they are used in context. (connection: interpreting domain-specific vocabulary such as “X-ray crystallography,” “bacteriophage,” or “nucleotide”)
CCSS.ELA-LITERACY.WHST.9-12.1: Write arguments focused on discipline-specific content. (connection: CER writing—claim, evidence, reasoning—based on classic heredity experiments)
CCSS.ELA-LITERACY.WHST.9-12.2: Write informative/explanatory texts, including the narration of scientific experiments and historical context.
Students use classic experiments to explain how DNA was identified as the genetic material.
This digital biology lesson guides students through the major experiments that demonstrated DNA is the molecule of heredity and led to the discovery of its structure. Students analyze historical data using Claim–Evidence–Reasoning (CER) to understand how scientists built and tested genetic theory over time.
Rather than memorizing names and dates, students work directly with experimental logic and results to determine how each study contributed to modern genetics.
Students examine four foundational experiments:
• Griffith (1928) — transformation in bacteria
• Avery, MacLeod, and McCarty (1944) — identification of DNA as the transforming factor
• Hershey and Chase (1952) — confirmation that DNA, not protein, is genetic material
• Chargaff (1949) — base-pairing relationships in DNA
For each experiment, students:
• analyze data or diagrams
• determine the claim supported by the results
• cite evidence
• justify conclusions using structured reasoning
Each investigation includes differentiated scaffolding options, allowing students to work:
• independently
• with claim hints
• or with visual guidance
Students then explore the discovery of DNA’s structure and the contributions of:
• Watson
• Crick
• Wilkins
• Rosalind Franklin
They evaluate how evidence supported the double helix model and reflect on how credit was distributed among scientists.
• DNA as genetic material
• Experimental design and interpretation
• Transformation
• Protein vs. DNA evidence
• Base-pair relationships
• Scientific reasoning (CER)
• History of science
• Builds deep conceptual understanding of genetics
• Shows how evidence changes scientific models
• Supports CER and argumentation
• Includes built-in differentiation
• Integrates science history with data analysis
• Works for guided instruction or independent work
• Minimal prep required
This resource is a digital interactive lesson (Google Slides compatible).
Includes:
✔ Student analysis slides
✔ Differentiated support options
✔ CER writing prompts
✔ Teacher answer key
✔ Exit ticket
• High school biology
• Genetics and heredity units
• History of science instruction
• CER skill development
• Inquiry-based learning
• Digital or hybrid classrooms
Grade & Course Recommendation:
Middle School:Grade 8 honors life science, during heredity or molecule of life units.
High School:Grade 9–11 Biology, as an introduction to molecular genetics.
To preview this lesson, click here.
Cross-Curricular Connections:
History of Science: Connects to the scientific process through the discovery timeline (Griffith, Avery, Hershey–Chase, Watson & Crick).
ELA Integration: Students summarize historical readings and defend evidence-based claims about scientific breakthroughs.
Art Integration: Creation of DNA structure models reinforces spatial understanding.
HS-LS1-1: Construct 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. (connection: understanding how DNA’s structure was discovered and why it is central to heredity)
HS-LS3-1: Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring. (connection: exploring historical experiments that established DNA as the molecule of inheritance)
HS-LS3-2: Make and defend a claim based on evidence that inheritable genetic variations may result from new genetic combinations through meiosis, errors during replication, and/or mutations caused by environmental factors. (connection: understanding DNA’s role in heredity and variation)
Science & Engineering Practices: Analyzing and interpreting data; Constructing explanations; Engaging in argument from evidence.
Crosscutting Concepts: Structure and function; Cause and effect; Systems and system models.
CCSS.ELA-LITERACY.RST.9-10.1 / RST.11-12.1: Cite specific textual evidence to support analysis of science and technical texts. (connection: reading passages on Franklin, Watson, and Crick to analyze scientific reasoning and ethics)
CCSS.ELA-LITERACY.RST.9-10.4 / RST.11-12.4: Determine the meaning of key scientific terms and phrases as they are used in context. (connection: interpreting domain-specific vocabulary such as “X-ray crystallography,” “bacteriophage,” or “nucleotide”)
CCSS.ELA-LITERACY.WHST.9-12.1: Write arguments focused on discipline-specific content. (connection: CER writing—claim, evidence, reasoning—based on classic heredity experiments)
CCSS.ELA-LITERACY.WHST.9-12.2: Write informative/explanatory texts, including the narration of scientific experiments and historical context.
