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Professor Program
Discussion Leader Activity: Bacterial DNA Movement
Author/Creator: Kristin Matulich - First Year PhD Student
Created for: Bio 97 Fall 2010
Activity Type: Small group worksheets and presentations
Time Needed in Discussion: 50 minutes
Learning Goals
 Students can list the important elements and processes associated with different bacterial DNA
movement processes (transposable elements, conjugation, pilus, transformation, transduction,
bacteriophage, recombination, etc.)
 Students can label diagrams that demonstrate these processes and explain the diagram to the class
 Students can explain the similarities and differences between the processes.
 Students can apply their understanding by successfully answering old exam questions on these
topics.
Abstract
Pre-class prep of diagrams and worksheet
Group work: Worksheet (1st half)
Class discussion
Group work: Worksheet (2nd half)
Class discussion
1 hour
15 minutes
10 minutes
15 minutes
10 minutes
Supplies
 Worksheet for each student. Students should print and bring their own.
 Worksheet figures to project onto white board. If a projector is not available, you can send
students to the board to draw the diagrams as they finish their labeling.
Pre-class prep
 Create worksheet with unlabeled figures, as in the sample worksheet (attached). It’s best to use
ones similar to ones from your own instructor’s lecture.
 Students must bring a copy of the worksheet to discussion. If your students are not accustomed
to printing and bringing something each week, you may want to email the worksheet to them and
instruct them to print and bring it.
In Class
1. Have students arrange themselves into groups of 3-4. Tell them to pull out the worksheet that
was emailed to them. Pass out extra worksheets if needed.
2. (5 min) Discussion Leader: “The worksheet we will be working on today reviews some of the
major concepts that we learned last week in lecture. Specifically, we will be learning about the
different ways DNA moves within and between bacterial cells. As you can see, the first page
of this worksheet has a figure with missing labels. Without using your notes, go ahead and
© 2010 by the HHMI-UCIrvine Professor Program. For non-commercial, educational use only.
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3.
4.
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Professor Program
spend the next 5 minutes trying to label this first figure using the keywords at the top of the
page. For this first 5 minutes, let’s all work individually.”
(10 min) After the students have had a chance to work on the worksheet individually, have
them get into small groups and come to an agreement as to what is the best choice for each of
the labels. Then, have them describe the process going on in the figure, and tell each student
to describe the process in the space below. At this point the students can also refer to their
notes. Walk around to the groups and answer questions.
(10 min) Project the first image onto the white board (or have a group that finished early begin
drawing it on the board). As a class, go through the steps in the figure. Call on groups to share
how they labeled the figure. After you have gone through the figure, read the multiple-choice
question. Tell students to raise their hand when they hear the correct answer. Go over the
correct answer, and call on students to explain why certain choices are incorrect.
(5 min) Move onto the second half of the worksheet. Again, tell students to spend 5 minutes
trying to label the figures individually, and without the help of their notes.
(10 min) After the students have had a chance to label the figure individually, have them
return to working their groups and complete the worksheet. Again, the students are allowed to
use their notes. Continue walking around and answer any questions the groups have.
(10 min) Project the second set of image onto the white board. As a class, go through the three
figures. Call on groups to describe the processes of transformation, transduction, and
conjugation. After you have gone through the figures, read the multiple-choice question. Tell
students to raise their hand when they hear the correct answer. Go over the correct answer,
and call on students to explain why certain choices are incorrect.
Ask students to straighten out the desks, and thank them for their participation.
Things to Ask or Emphasize
 In order for all of these processes to complete, the foreign DNA must be integrated into the new
DNA. Successful recombination must occur.
 Make sure students understand the difference between a transduction and a normal viral
infection, as well as the difference between a plasmid and the circular bacterial chromosome.
Comments
Students find it very difficult to keep the details of transformation, transduction, and conjugation
clear, so this figure that displays all three processes side by side was very useful. The students also
seemed to gain a lot from having to describe the figure in their own words.
© 2010 by the HHMI-UCIrvine Professor Program. For non-commercial, educational use only.
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Professor Program
Week 6: BioSci 97 Discussion Section
Part 1: Genetic Information Transfer Within A Cell
Keywords: transposable element, DNA polymerase, transposase, chromosomal DNA
1. Label the Figure.
2. Describe in words what is going on.
3. Application: Test Question
Which of the following statements is FALSE? Transposable elements...
A. Require host ribosomes for protein production.
B. Contain the gene for a protein that cuts them out of genomic DNA.
C. Transpose between bacterial cells.
D. More than one of the statements above is FALSE.
© 2010 by the HHMI-UCIrvine Professor Program. For non-commercial, educational use only.
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Professor Program
Part 2: Genetic Information Transfer Between Cells
Keywords: transformation, transduction, conjugation, pilus, bacteriophage, host cell, cell-to-cell
contact
4. Label the Figure.
5. Describe in words what is going on.
A.
B.
C.
6. Application: Test Question
Which of the following statements does NOT describe transduction?
A. Faulty head stuffing
B. Requires the lytic cycle
C. Requires fragmentation of the bacterial genome
D. Enables movement of genes within a bacterial cell’s genome.
© 2010 by the HHMI-UCIrvine Professor Program. For non-commercial, educational use only.