Chapter 13

Question 1

recombinant DNA

Answer 1

single DNA molecule containing DNA sequences from two or more sources

Question 2

what role do restriction enzymes play in DNA manipulation?

Answer 2

cutting DNA into pieces

Question 3

what role does gel electrophoresis play in DNA manipulation?

Answer 3

analysis and purification of DNA fragments

Question 4

what role does DNA ligase play in DNA manipulation?

Answer 4

joins DNA fragments together in novel combinations

Question 5

how can bacteria use restriction enzymes to defend against invasions

Answer 5

produce restriction enzymes that cut double-stranded DNA molecules into smaller, noninfectious fragments

Question 6

restriction site

Answer 6

a specific sequence of bases where restriction enzymes cleave

Question 7

in what manner do enzymes cut the DNA?

Answer 7

leave a short sequence of single stranded DNA at each end

Question 8

what information about DNA can gel electrophoresis yield?

Answer 8

number of fragments, sizes of fragments, relative abundance of a fragment

Question 9

DNA ligase

Answer 9

catalyses the joining of DNA fragments by making phosphodiester bonds between them

Question 10

how are Okazaki fragments joined during DNA replication?

Answer 10

by DNA ligase

Question 11

clone

Answer 11

produce many identical copies

Question 12

transformation

Answer 12

inserting recombinant DNA into host cells

Question 13

transfection

Answer 13

transformation but specific to when host cells are derived from an animal

Question 14

transgenic

Answer 14

host cell or organism that contains recombinant DNA

Question 15

selectable marker

Answer 15

helps grow only the transgenic cells

Question 16

electroportaion

Answer 16

a short electric shock used to create temporary pores in the membranes through which the DNA can enter

Question 17

replicon

Answer 17

segment of DNA that contains an origin of replication

Question 18

vector

Answer 18

part of a carrier DNA sequence that the newly introduced DNA can enter the host cell with

Question 19

plasmids

Answer 19

small, circular DNA molecules that replicate autonomously in many prokaryotic cells

Question 20

reporter gene

Answer 20

any gene whose expression is easily assayed

Question 21

genomic library

Answer 21

collection of DNA fragments that together comprise the genome of an organism

Question 22

cDNA

Answer 22

complementary DNA

Question 23

cDNA library

Answer 23

transcription pattern of the cells in the sample at a certain point in time

Question 24

RT-PCR

Answer 24

using reverse transcriptase to make cDNA from RNA and then using PCR to amplify a specific sequence from the cDNA

Question 25

homologous recombination

Answer 25

involves an exchange of DNA between molecules with identical, or nearly identical, sequences

Question 26

stem cell

Answer 26

unspecialised cell that divides and differentiates into specialised cells

Question 27

RNA interference

Answer 27

mechanisms for preventing mRNA translation

Question 28

antisense RNA

Answer 28

RNA that binds by base pairing to the sense bases on the target mRNAs

Question 29

why do siRNAs target specific mRNA molecules?

Answer 29

their sequences exactly match the target sequences in the mRNAs

Question 30

what can miRNAs do since they do not match their targets perfectly?

Answer 30

reduce the expression of multiple, partially matching genes

Question 31

expression vectors

Answer 31

vectors that also have extra sequences needed for the foreign gene to be expressed in the host cell

Question 32

inducible promoter

Answer 32

responds to a specific signal

Question 33

tissue-specific promoter

Answer 33

expressed only in a certain tissue at a certain time

Question 34

signal sequences

Answer 34

can be added so that the gene product is directed to an appropriate desgination

Question 35

pharming

Answer 35

the production of pharmaceuticals in farm animals or plants

Question 36

advantages of recombinant DNA technology

Answer 36

ability to identify specific genes, ability to introduce any gene from any organism into a plant or animal species, ability to generate new organisms quickly

Question 37

bioremediation

Answer 37

the use by humans of other organisms to remove contaminants from the environment