Genetics II Applications

Question 1

Basic components of vectors

Answer 1

Must allow insertion of foreign DNA

Must maintain ability to replicate in bacterial or eukaryotic host

Question 2

Different vectors and size of DNA incorporated

Answer 2

Plasmid: up to 20 KB
Bacteriophages: up to 25 KB
Cosmid vectors: up to 45 KB

Question 3

Most cloning vectors are engineered to have what three qualities?

Answer 3

1. Site for foreign DNA insertion
2. Means for selecting bacteria that have incorporated vector
3. Means for identifying bacteria that have incorporated plasmids containing inserted DNA

Question 4

What two things are expression vectors engineered to have?

Answer 4

1) DNA sequences to facilitate replication in bacteria

2) Transcription of the gene into mRNA

Question 5

Restriction Enzyme

Answer 5

Cleaves at specific palindromic base sequences, may make blunt or staggered cut

Question 6

DNA ligase

Answer 6

Used to join vector to DNA fragments, which creates recombinant DNA

Question 7

Two ways of genomic library generation?

Answer 7

1) Clone all fragments resulting from chromosomal DNA cleavage
2) Convert mRNA for specific proteins into cDNA to generate a cDNA library

Question 8

Reason to look into using bacteriophage therapy?

Answer 8

Increasing resistance of bacteria to antimicrobials, could use bacteriophages that cause lysis of bacterial cells

Question 9

Three problems with use of bacteriophage therapy?

Answer 9

1) Extreme specificity of phage-host interaction, takes time to identify then grow
2) Circulating bacteriophages rapidly cleared by spleen
3) Unknown effect of large amounts of circulating bacteriophage on human host