2: Biotechnology

Question 1

What are three tools of molecular cloning?

Answer 1

1. Cloning vector
2. Restriction enzyme/endonuclease
3. DNA ligase

Question 2

What are the characteristics of plasmids?

Answer 2

• Small circular double-stranded DNA molecules
• Naturally found within a bacteria cell
• Physically separated from host’s cell chromosomal DNA
• Replicate independently of host cell’s chromosomal DNA (have Ori-orignial site of replication)
• Carry non-essential genes that provide a benefit to host cell under certain conditions

Question 3

What is a cloning vector?

Answer 3

A plasmid that has been engineered to carry certain sequences so that it can be used as a tool in molecular cloning

Question 4

What are some features of cloning vectors? (4)

Answer 4

• Origin of replication (Ori)
• Selectable marker
• Multiple cloning site (MCS)
• Colour selection gene

Question 5

Describe the Origin of Replication (Ori)

Answer 5

• An AT-rich replication start sequence, which allows the vector to replicate independently of the host’s chromosomal DNA

Question 6

Describe the selectable marker

Answer 6

• A gene whose gene product allows identification of cells carrying vector
• (usually) an antibiotic resistance gene; its gene product (i.e. protein provides resistance to e.g. ampicillin, kanamycine, tetracycline

Question 7

Describe the multiple clonin site (MCS)

Answer 7

• DNA region where DNA fragment of interest is inserted

- Made up of many restriction site sequences, that are not found elsewhere on the cloning vector

Question 8

Describe the colour selection gene

Answer 8

Provides colour-based selection of cells that carry a vector that has had a DNA fragement inserted into the MCS