Chapter 9.2: Cloning DNA Fragments

Question 1

What are plasmids?

Answer 1

 The simplest vectors are minute circles of double-stranded DNA known as plasmids that can gain admission to and replicate within many kinds of bacterial cells, independently of the bacterial chromosomes

Question 2

What are selectable markers?

Answer 2

 Antibiotic resistance genes and other vector genes that make it possible to pick out cells harboring a particular DNA molecule are called selectable markers

Question 3

What is transformation?

Answer 3

o Transformation is the process by which a cell or organism takes up a foreign DNA molecule, changing the genetic characteristic of that cell or organism

Question 4

What are the largest capacity vectors?

Answer 4

 The largest capacity vectors are artificial chromosomes: recombinant DNA molecules that combine replication and segregation elements in such a way that they behave like normal chromosomes when introduced into a host cell

Question 5

What is a genomic library?

Answer 5

o Genomic library: a long-lived collection of cellular clones that contains copies of every sequence in the whole genome inserted into a suitable vector

Question 6

Define molecular cloning

Answer 6

• The process that uses living cells both to isolate a single fragment of DNA from a complex mixture and to make many exact replicas of that fragment is called molecular cloning

Question 7

Describe the process of molecular cloning

Answer 7

o In the first, DNA fragments are inserted into specialized chromosome like carriers called cloning vectors, which ensure the transport, replication, and purification of individual DNA inserts o In the second step, the combined vector-insert molecules are transported into living cells, and the cell make many copies of these molecules  Because all copies are identical, the group of replicated DNA molecules is known as a DNA clone

Question 8

How is a recombinant DNA molecule generated?

Answer 8

o The cutting and splicing together of vector and inserted fragment—DNA from two different origins—creates a recombinant DNA molecule

Question 9

What must a vector contain?

Answer 9

 One to provide a means of replication for the vector and the foreign DNA inserted into it  The second to signal the vector’s presence to an investigator by conferring a detectable property on the host cell