Part 3/4: Tools of Molecular Genetics

Question 1

Recombinant DNA:

Answer 1

• A DNA molecule that is composed of DNA from different sources.

Question 2

Plasmid:

Answer 2

• Small circular DNA molecule that replicates independently of the genome.
• Used extensively as a vector for DNA cloning.

Question 3

DNA library:

Answer 3

• Collection of cloned DNA molecules, representing an entire genome (genomic library) or copies of the mRNA produced by a cell (cDNA library)

Question 4

Cloning:

Answer 4

• Making many identical copies of a cell or a cDNA molecule or an organism.

Question 5

Genomic Library:

Answer 5

• collection of cloned DNA molecules, representing an entire genome.
• constructed using restriction enzyme and ligase
• CONTAINS INTRON SEQUENCES

Question 6

cDNA library:

Answer 6

• collection of the copies of the mRNA produced by a cell
• NO INTRON SEQUENCES
  
  • ​cDNA is transcribed from processed mRNA via reverse transcriptase

Question 7

Genes can be isolated from a genomic library utilizing:

Answer 7

• hybridization with radioactively-labeled cDNA

Question 8

Green fluorescent protein (GFP):

Answer 8

• Fluorescent protein (from a jellyfish) that is widely used as a marker for monitoring the movement of proteins or expression and localizaCon of proteins in living cells.

Question 9

Reporter gene:

Answer 9

• Introduced gene encoding a protein whose actvity is easy to monitor experimentally.
• Usually joined to a regulatory sequence, which will then switch on the reporter gene in the normal context in which its own gene is usually expressed.

Question 10

Vector:

Answer 10

• a plasmid that is used to carry a fragment of DNA into a recipient cell for the purpose of gene cloning or gene expression.

Question 11

Gene replacement:

Answer 11

• Replacement of a normal gene in an organism with one that has been mutated in vitro, used to investigate the gene’s function.
• ONLY MUTANT GENE EXPRESSED

Question 12

Gene knockout:

Answer 12

• A specific gene has been inactivated, e.g. by introducing a deletion in its DNA
• NO ACTIVE GENE EXPRESSED

Question 13

Transgenic organism:

Answer 13

• An animal that has stably incorporated one or more genes from another cell or organism and can pass them on to a successive generations.

Question 14

What two techniques allow for the amplification of DNA sequences?

Answer 14

1. PCR
2. cloning in bacteria

Question 15

A southern blot detects:

Answer 15

Large deletions in DNA.

(Using Restriction Fragment Length Polymorphism technique)

“rif-lip”

Question 16

Allele specific oligonucleotides are most useful for detection of what kind of mutations?

Answer 16

• common point mutations for a specific disease
  
  • i.e. SCA and thallassemias