Conjugation &
Transformation
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Lilli Howard
BIOL/GEN 313
Dr. Vollbrecht
03/25/14
1. Prototrophic: ____________________________________________________________
2. Auxotrophs: ____________________________________________________________
3. Plasmid: _______________________________________________________________
4. Episomes: ______________________________________________________________
5. Define conjugation and transformation. What are the similarities and differences?
6. What is the difference between transfer of the F Factor and F Factor integration? (Use
Pictures)
7. What types of matings are possible between F+, F- and Hfr, cells? What outcomes do
these matings produce? What is the role of F factor in conjugation?
8. Explain how interrupted conjugation and transformation can be used to map bacterial
genes.
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
9. Which is true of plasmids?
a. They are composed of RNA
b. They normally exist outside of bacterial cells
c. They possess only a single strand of DNA
d. They contain an origin of replication
10. Conjugation between an F+ and an F- cell usually results in o
a. Two F+ cells
b. Two F- cells
c. An F+ and an F- cell
d. An Hfr cell and an F+ cell
11. Interrupted conjugation was used to map three genes in E. coli. The donor genes first
appeared in the recipient cells at the following times: gal, 10 minutes; his, 8 minutes; pro,
15 minutes. Which gene is in the middle?
12. DNA from a bacterial strain with genotype his- leu- thr- is transformed with DNA from a
strain that is his+ leu+ thr+. A few leu+ thr+ cells and a few his+ thr+ cells are found, but
no his+ leu+ cells are observed. Which genes are farthest apart?
13. A bacterium of genotype a+ b+ c+ d+ is the donor in a co-transformation mapping
experiment. The recipient is a- b- c- d-. Data from the transformed cells are as follows.
Co-transformed alleles
Number of colonies
a+ b+
2
a+ c+
0
a+ d+
5
b+ c+
5
b+ d+
0
c+ d+
0
What is the order of the genes?
a) a c b d
b) a d c b
c) c b a d
d) c a d b
14. The table that follows shows the results of interrupted-mating experiments with three
different Hfr strains. What is the order of the genes, starting with C?
Hfr Strain
1
2
3
Order of Transfer
A, B, E, D, F
D, F, C, G, A
D, E, B, A, G
a) C, G, A, D, F, B, E
b) C, F, D, B, A, E, G
c) C, B, E, D, F, G, A
d) C, G, A, B, E, D, F
e) C, D, F, G, A, B, E
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu