mock exam Qs /- JJ

Question 1

Out of the features of a plasmid, which one allows for the selection of bacterial clones that have incorporated cloned DNA?

Answer 1

The antibiotic resistant gene

Question 2

Bacteria such as E. coli is used for expression of cloned DNA bc:

Answer 2

They grow v fast
Inexpensive culture conditions
Allow protein production in high yields
Many molecular tools available

Question 3

You know that mutation triggers the expression of a gene. Which of the following techniques can you use to identify the gene affected?

Answer 3

Northern blot and in situ hybridisation

Question 4

What is the main goal of microarray experiment?

Answer 4

To investigate the expression of thousands of genes at the same time

Question 5

Phenotype is:

Answer 5

the observable traits of an individual

Question 6

Prince Leopold suffered haemophilia because:

Answer 6

Queen victoria was a carrier

Question 7

Which RNA polymerase subunit is not part of the processive core and gets released after initiation?

Answer 7

Sigma

Question 8

Which sigma factor will not bind to -10 and -35 region?

Answer 8

sigma 54

Question 9

2 component regulatory systems involve

Answer 9

A histidine kinase that phosphorylates a regulator when an inducer is present

Question 10

the Lac operon:

Answer 10

responds to presence of lactose using a respressor and glucose using an activator that binds to cAMP

Question 11

When checking the resulting products of PCR by gel electrophoresis

Answer 11

shorter fragments will migrate faster

Question 12

Different restriction enzymes

Answer 12

Recognise specific sequences and produce ends that are occasionally compatible

Question 13

DNA ligases are responsible for

Answer 13

the formation of phosphodiester bonds between DNA fragments

Question 14

What steps are part of cloning bacteria?

Answer 14

DNA amplification
DNA digestion
DNA ligation
Electroporation

Question 15

A plasmid that is transfected into animal cells and does not contain an origin of replication but carries a selection marker may lead to…

Answer 15

stable integration in the chromosome and spread in the population in the presence of a selection marker

Question 16

Northern blot allows

Answer 16

To determine the presence and size of a transcript

Question 17

How would you identify the cells expressing a particular gene in the development of the endoderm of D. melanogaster?

Answer 17

In situ hybridisation

Question 18

Protein fusions allow studying

Answer 18

gene expression thanks to the presence of a reporter

Question 19

the most probable outcome of the cross of two heterozygous individuals carrying a dominant mutation is:

Answer 19

75% will have mutant genotype and phenotype

Question 20

Outcome of two heterozygous individuals each carrying a recessive mutation is

Answer 20

75% mutant genotype

25% mutant phenotype

Question 21

mutations are always

Answer 21

changes in DNA sequence

Question 22

minimal requirement to be affected with Huntingtons disease is:

Answer 22

mother is a carrier