Lesson Plan Template: General Lesson Plan
Learning Objectives: What should students know and be able to do as a result of this lesson?
Student will be able to demonstrate understanding of gene expression by transcribing a DNA sequence and translating it to a protein.
Prior Knowledge: What prior knowledge should students have for this lesson?
This activity should be used after an initial introduction to transcription and translation as a means of understanding how genes are expressed.
Students should have prior knowledge of:
- Base pairing rules for replication and transcription
- DNA replication process
Students should have prior knowledge of the following benchmark from 7th grade life science
SC.7.L.16.1 - Understand and explain that every organisms requires a set of instructions that specifies its traits, that this hereditary information (DNA) contains genes located in the chromosomes of each cell, and that heredity is the passage of these instructions from one generation to another.
Students should have prior knowledge of the following benchmarks from high school biology
SC.912.L.16.3 - Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic information.
SC.912.L.16.9 - Explain how and why the genetic code is universal and is common to almost all organisms
Familiar Vocabulary: Codon, DNA, Gene, Genetic Code, mRNA, Polypeptide, rRNA, tRNA, Replication, Transcription, Translation
Guiding Questions: What are the guiding questions for this lesson?
How is the expression of genes displayed in individuals? (students should be able to give examples of human traits)
Why is gene expression different from one individual to another? (students should be able to relate that DNA holds the codes for genes and those genes exhibit different traits)
In this exercise/activity what are the types of genes to be expressed and what initiates the expression of that particular gene? (students should be able to relate that the different genes codes for different toppings of their ice cream sundae and it is initiated by the DNA sequence)
Describe the process of transcription and translation. (students should be able to explain that transcription assembles a complement DNA thus creating an mRNA and translation is the process of building a protein from amino acids)
Why will one person have a gene that expresses chocolate ice cream while another will have a gene that expresses vanilla? (students should be able to explain that the genes are different due to differences in the original DNA sequences)
What role does base pairing play in transcription? (students should understand that A pairs with T in DNA, but there is no T in RNA - RNA contains a U: this is important to the replication process.)
How does base pairing work in a cell? (students should be able to distinguish between A-T/C-G in DNA replication where RNA for Transcription and Translation A-U/C-G)
Teaching Phase: How will the teacher present the concept or skill to students?
Students will be given a strip of DNA upon entrance into the classroom (print, copy and cut sequences into strips).
Determine the number of genes their sequence contains (10)
Verify that students get 10 gene sequences as their answer.
Show the 7 minute video reviewing Transcription and Translation that explains gene expression. https://www.youtube.com/watch?v=h5mJbP23Buo The transcription and translation should draw upon students' prior knowledge of genetics and DNA structure.
Explain to students that they will using the DNA code they received upon entering the class to show expression of genes in an ice cream sundae. They will be taking their code from DNA - transcribing it into mRNAs - translating it into polypeptide chains that will allow the expression of genes (topping for their ice cream sundae). Once they have completed their gene expressions they will be using it to build their own ice cream sundae based upon their expression.
Guided Practice: What activities or exercises will the students complete with teacher guidance?
Teacher will guide students in completion of a gene sequence. All ice cream sundaes must start with a bowl.
On the board/overhead, etc write:
TAC TTT CTA ACT (4 codons)
(mRNA)AUG AAA GAU UGA = Transcription
(amino) Met- Lys- Asp- Stop (remind AUG = start) = Translation
This gene codes for a bowl!!!!
Inform students: for simplicity, the gene sequences given are much smaller than "real" gene sequences found in living organisms. Each gene has two versions that result in a different trait being expressed.
Teacher needs to hand out the instructions and gene expression chart for students to continue with their independent practice (see attachment).
Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
Students will complete the transcription of their DNA code (see attachment with answer key).
Teacher should walk around the room checking to make sure students are performing their transcription correctly.
Students will complete the translation of their mRNA code using the genetic code chart (see attachments for sample of chart and answer key).
Teacher should walk around the room checking to make sure students are performing their translations correctly.
Students will determine the expression of their gene based upon the amino acid sequence they determined (see attachments for gene expression chart).
Teacher should walk around the room checking to make sure students are using the chart correctly.
Students will assemble their ice cream sundaes using given supplies based on the code their genes express. (It may be advantageous to recruit help/assistance from other teachers, aides, etc for cleanliness, quantity management, etc).
Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Teacher will lead discussion regarding why some students have chocolate ice cream and others have vanilla as their initial gene 1 sequence.
Closing questions and discussion:
- What in the cell is actually building a new RNA strand, and where does this take place?
- What in the cell is actually building the protein, and where does this take place?
- How could we change our ice cream activity to make it more realistic?
Students will complete the activity by composing an essay with the explanation of why their ice cream sundae may/may not have looked similar to their classmates and then relate it to an explanation of why they may/may not have similar phenotypic characteristics as their parents (visable and non visable phenotypes).
Note: Responses will vary based on combinations.
Students will construct an ice cream sundae expressing the correct genes as coded for by their given DNA strand.
Essays will be read for accuracy of information and understanding of the concept of gene expression.
Students will be working through their DNA sequence, demonstrating an understanding of base pairing by making a mRNA strand (transcription) starting with AUG and ending with either UAA, UAG or UGA (stop codons).
Students will take their mRNA code and correctly use a genetic code map to translate their codon into an amino acid.
Students will take their amino acid chain (polypeptide, protein) to match the "gene" expressed for the building of their ice cream sundae.
Correct coding of genes will result in an ice cream sundae with the correct components (gene expression).
** Students should be allowed to continue at their own pace while teacher answers questions and verifies correct responses for their particular code.
Feedback to Students
After students have completed their polypeptide sequences and before they build their Ice Cream Sundae check to verify the proteins/genes are correctly coded. Students that do not have the correct expression of their gene may go back and find their errors.