Week 8

Question 1

1.Which statement about plasmids is incorrect?

Answer 1

Plasmids are essential for survival of their host organism

Question 2

2.Which statement about fungi is incorrect?

Answer 2

Fungi are known as the “workhorses of molecular biology”

Question 3

3.Which is NOT a reason for low yields of proteins expressed in yeast cultures?

Answer 3

The plasmid is high copy number
Feedback: A high copy number would be a good thing – more plasmid, more protein production

Question 4

4.Which is NOT a reason Arabidopsis is used as a model organism?

Answer 4

It’s an unusual, attractive-looking plant
Feedback: it’s not a particularly attractive plant; it’s rather weedy

Question 5

5.Codon bias can be overcome by which scenario?

Answer 5

Genetically engineering host organisms to express rarer tRNAs.

Modifying the gene so that the codons are recognised by more abundant tRNAs

Question 6

6.What is the first step in genetically modifying a plant

Answer 6

Identification of a gene that will confer a useful trait
Feedback: Can’t do anything until we know what gene we want!

Question 7

7.What is DNA coated onto when transforming cells with a particle gun?

Answer 7

Gold
Feedback: Yes, it’s stable, inert and you can store DNA coated gold particles for a year

Question 8

8.Which statement about yeast recombinational cloning is NOT true?

Answer 8

A Type IIS restriction enzyme is used to cleave the plasmid at insertion sites ready for ligation by DNA ligase

Question 9

9.Which one of the following statements regarding insulin production is NOT true?

Answer 9

E. coli can form preproinsulin & process this peptide into insulin naturally

Question 10

10.What are the four main GM crops grown worldwide?

Answer 10

Soybean, cotton, maize and oilseed rape