Course Guide Chapter 18: Recombinant DNA Technology

Question 1

What is the function of restriction endonucleases?

Answer 1

enzymes located from prokaryotes that recognize a specific DNA sequence and cleave the DNA at that recognition site or another place

Question 2

What is the function of DNA polymerase?

Answer 2

used to make DNA in vitro

Question 3

What is the function of DNA ligase?

Answer 3

catalyze the covalent bonding of the 3’ and 5’ ends of two DNA strands

Question 4

What is the function of reverse transcriptase?

Answer 4

an RNA dependent DNA polymerase; uses an RNA template to make a complementary DNA

Question 5

What is the purpose of gel electrophoresis?

Answer 5

used to fractionate DNA or RNA fragments based on their size

Question 6

What is the purpose of restriction fragment length polymorphism?

Answer 6

used to identify differences in the restriction pattern of a specific gene or DNA region between several individuals of a species or several related species

Question 7

What is the purpose of radiolabeling DNA fragments?

Answer 7

using a radioisotope or fluorescent label to identify a DNA fragment in an organism

Question 8

What is the purpose of DNA sequencing?

Answer 8

an in vitro DNA synthesis using a DNA template is done to extend the new strand of DNA from the primer in a suitable buffer

Question 9

What is the purpose of polymerase chain reaction (PCR)?

Answer 9

used to amplify large amounts of DNA from small amounts of samples

Question 10

What is southern hybridization?

Answer 10

hybridizing a labeled DNA probe to the target DNA sequences immobilized on a nylon membrane; used to study the genome organization of a particular gene and determine the approximate number of copies of a specific gene

Question 11

What is northern hybridization?

Answer 11

hybridizing a labeled DNA probe with size-fractioned RNA immobilized on a nylon membrane; used to determine the RNA levels for a particular gene at different stages or in different tissues or organs of an organism

Question 12

What is western hybridization?

Answer 12

involves protein-antibody interaction; a specific protein (antigen) is recognized first by a primary antibody which is then recognized by a secondary antibody conjugated to a fluorescent probe or an enzyme. This enzyme can convert a chromogenic substrate into a colored substance for the detection