Using Scientific Discourse
Students learn how to apply scientific reasoning to new problems and then communicate about it with peers.
Teacher: Mary Murphy
School: The Urban School of San Francisco (Private), San Francisco, CA
Discipline: Science (Biology)
Lesson Topic: Transcription and translation: Cracking a code
Lesson Month: January
Number of Students: 13
Featured Lesson’s Student Goals:
- Content objectives – Describe in detail the connection between genotype and phenotype, or gene and protein; identify and practice the steps involved in protein synthesis (transcription and translation); crack a “code” from our kidnapping mystery using transcription and translation as tools
- Literacy/language objectives – Practice using, in context, all of the vocabulary involved in the processes of transcription and translation.
- Engagement/interaction objectives – Collaborate with peers to “crack a code”
Next Generation Science Standards
Students who demonstrate understanding can:
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. [Assessment Boundary: Assessment does not include identification of specific cell or tissue types, whole body systems, specific protein structures and functions, or the biochemistry of protein synthesis.]
Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science, and Technical Subjects
Determine the central ideas or conclusions of a text; trace the text's explanation or depiction of a complex process, phenomenon, or concept; provide an accurate summary of the text.
Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 9–10 texts and topics.
Translate quantitative or technical information expressed in words in a text into visual form (e.g., a table or chart) and translate information expressed visually or mathematically (e.g., in an equation) into words.
This 2.5-day unit was focused on protein synthesis and fell in the middle of the curriculum year. It built upon a previous unit on inheritance in which students learned about the structure of DNA and its role in genetics. Prior to the inheritance unit, the class completed a unit on forensic science and were introduced to the crime scene and mysterious disappearance of Dr. Martin Meselson (the story on which this lesson’s code-cracking activity was based.) This lesson fell in the middle of the unit.
Before the Video
Ms. Murphy gave students a pre-lesson reading assignment on transcription and translation, the two processes that make up protein synthesis. She also provided a worksheet to help them identify overarching points and key vocabulary. In class the following day (the day before this lesson), Ms. Murphy reviewed what students had already learned about DNA in the previous unit and used diagrams and drawings to discus the steps that make up the processes of transcription and translation. Throughout the discussion, Ms. Murphy stopped periodically for “cocktail parties” during which students got up out of their seats and found a partner to explain the steps of each process, using a diagram.
During the Video
Ms. Murphy began the lesson with a warm-up question to help students apply their understanding of transcription and translation (the question was about poison/disease blocking a step within one of the processes). She revisited the steps of both transcription and translation. Students then narrated the steps of transcription and translation without using diagrams or notes—first in pairs, then in table groups, and finally as a whole class. Ms. Murphy reviewed the relevance of the two processes and the primary question of understanding: How does DNA work as a code? Using this knowledge, students participated in the code-cracking activity to solve the mystery of Dr. Martin Meselson’s disappearance.
After the Video
After this lesson, Ms. Murphy debriefed with students and made connections to the prior forensic science unit. She talked in more detail about transcription and RNA processing. She posed a real-life application question by asking students about the relationship between protein synthesis and stem cells. This served as a transition into the next unit, which focused on gene regulation.
To prepare for this lesson, Ms. Murphy thought about the pacing—how to give students enough time to practice their understanding of transcription and translation, but also to complete the activity without feeling rushed (which, she felt, could potentially lead to massive confusion). She identified key vocabulary and created the reading guide. For the code-cracking activity, Ms. Murphy determined combinations of three-letter codes to represent English words without having any overlap, created a master matrix of the answers, and prepped the index cards.
To participate in this lesson, students needed to understand the structure of DNA and cell organelles and to be able to think about biology as a language (e.g., how the meaning of a word can be determined using word structure, etc.).
Ms. Murphy had students review their homework worksheet in groups to give them an opportunity to verbalize their understanding, ask for and receive help from peers, and further practice protein synthesis. She walked around the room to observe pairs and groups and gave one-on-one time to students who needed it.
Throughout the year, Ms. Murphy emphasized the importance of collaboration (in her classroom and in the field of science); she had students work in randomly generated groups to share information and ideas and learn from each other. In this lesson, students paired up to review homework and vocabulary from the introductory reading and to narrate the story of transcription. They worked in small teams during the code-cracking activity.
To manage group interaction, Ms. Murphy often facilitates group conversations and interjects when students are heading down the wrong path. She talks with students about peer collaboration and interaction in performance assessments and reinforces the collaborative components of participation such as listening, brainstorming, and sharing ideas with others.
Resources and Tools
- Student notebooks
- Color-coded diagrams on transcription and translation
- Index cards, tape, envelopes, colored pencils, and answer matrix for the code-cracking activity
- Projector, Smart Board, and Boardnotes
- Transcription & Translation: Reading Notes handout
- Protein Synthesis quiz handout
- Homework worksheet reviewing transcription and translation handout
During the lesson, Ms. Murphy gauged understanding by doing a homework check, listening and observing students during the warm-up question, and noticing individual participation during the code-cracking activity.
The pair work (“cocktail party”) gave students an opportunity to evaluate their own understanding: if they could explain the processes of transcription and translation, then they understood them. If they could not help another student, they knew they needed better understanding. During the code-cracking activity, students knew they were doing the transcription and translation correctly if they “cracked the code” to reveal the story of Dr. Martin Meselson’s disappearance.
At the end of this unit, Ms. Murphy gave students a quiz on protein synthesis.
Impact of Assessment
Ms. Murphy makes modifications to her lesson plans based on students’ understanding. In this lesson, after asking the warm-up question, she felt that her students were on such a good roll with transcription and translation that she decided on the spot to cut and move to another time a planned discussion about the processing of RNA.