Lesson Plan 17
Biology
Shawn P. Schwartz
30 Students
OBJECTIVE:
Students will illustrate how restriction enzymes work by piecing together parts of a puzzle. Students will then apply this knowledge to help them analyze genetic evidence from the scene of a crime as well as to help them comprehend how a DNA sample can be used in crime scene investigation to catch the culprit.
MATERIALS:
-Spiral notebook
-Pen/Pencil
-Biology textbook
-Overhead projector
-Prepared transparency with a different example of a puzzle with separate samples of DNA
-Restriction enzyme worksheet puzzle
-Scissors
-Tape
-Paper
-Personal computer
-Projector
NOTES:
Restriction enzymes are subject matter that can be very difficult to comprehend. Make sure that all students in every group stay on task. Work with the students who seem to be having difficulty understanding the subject matter individually until every student understands how restriction enzymes work and how they can be applied to crime scene investigation.
STEPS:
ANITICIPATORY SET: (2 minutes) Ask the students to visualize what it would be like to be a detective on a crime scene investigation. What tools does a detective need to solve a crime?
1. (3 minutes) Take class attendance, get all of the students settled, and have students pass up homework.
2. (10 minutes) Have students open the biology textbook to Chapter 15. Call on individual students randomly to each read aloud one paragraph in the chapter related to restriction enzymes and gel electrophoresis.
3. (10 minutes) Turn on the overhead projector and show the students the prepared transparency with a different example of a puzzle with separate samples of DNA. Demonstrate how to catch the fictitious culprit by analyzing the DNA evidence (explained in further detail in Step 4).
4. (20 minutes) Randomly divide the students into six groups of five students. Pass out the restriction enzyme worksheet puzzle to each group. On the worksheet, students are presented with four samples of DNA: one from the crime scene, and three others from each of the suspects. Students will use scissors in the place of restrictive enzymes to cut the DNA samples only where they see the sequences shown on the hand-out. Students will then chart the base pairs, and compare it to the actual gel electrophoresis created from the DNA found on the crime scene. Finally, the students will tape the fragments on the paper according to the number of base pairs indicated on the chart, compare the three patterns to the gel electrophoresis created from the DNA found on the crime scene, and determine the culprit. After every group has fingered a culprit, make sure that every group understands how restriction enzymes work and that each group has correctly identified the criminal. Finally, explain to the students that restriction enzymes relate to social justice in a positive way by helping society catch criminals. However, there are also many negative aspects of DNA evidence, including that it can easily be used to frame an innocent person.
5. (15 minutes) Use my personal computer and the projector hooked up to it to show students how to navigate to http://www.umich.edu/%7Eexppro/info.html by going to the Hip Hop Circuit website and clicking on Teachers, then Expository Writing, and finally Information about Oral and Written Exposition. Call on individual students randomly to each read aloud one paragraph of the web page. After the page is read, explain to the students that they will be writing a two hundred-word expository writing sample based on the sequential pattern depicted on the website. Click on “view” under “Graphical Organizer/Sample Passages” to show the students an example of this type of writing. By using the sequential pattern of expository writing, students will outline how they fingered the culprit by using restriction enzymes in this classroom activity.
FOLLOW-UP ACTIVITY:
Students will write a two hundred-word, sequential, expository paper that outlines the restriction enzyme activity they performed in class. This activity will allow students to make use of a format of writing that they can use in other classes as well as review the main points of the crime scene investigation activity that they performed in class. This activity will promote greater comprehension of how restriction enzymes can be applied to daily life. Students will be assessed by whether their expository writings meet the guidelines of the assignment and the guidelines outlined on the website. If the students’ essays meet the criteria of listing the most important parts of the activity, using proper sentence structure and development, as well as demonstrating original thought, then their assignments will receive an “A”.
LITERACY ASPECT:
In this lesson many students will utilize their reading skills by reading aloud one paragraph in the chapter related to restriction enzymes and gel electrophoresis. Many students will also make use of their reading skills by reading aloud one paragraph from the Information about Oral and Written Exposition website. Finally, as a homework assignment, every student will develop their writing skills by creating a two hundred-word, sequential, expository writing outlining the restriction enzyme activity they performed in class.
REFLECTION/RESPONSE:
The students paid attention to the subject matter because of the usage of a variety of audiovisuals to teach them as well as the hands-on activity of using a restriction enzyme worksheet and a gel electrophoresis sample to catch a criminal. However, this lesson requires some preparation, so make sure to schedule the appropriate amount of time in the morning for preparation of the transparency with a different example of a restriction enzyme puzzle with separate samples of DNA.