Chapter 12 - Manipulating DNA: Tools and Techniques

Question 1

gene technology

Answer 1

a broad field which includes analysis of DNA as wells genetic engineering and other forms of genetic modification

Question 2

genetic engineering

Answer 2

artificial manipulation of genes
adding or subtracting genes, or changing the way genes work
genetically modified organisms (GMO)

Question 3

benefits of gene technology

Answer 3

increasing crop and livestock production
preventing and fighting disease
reducing pollution and waste
producing new products
detecting and preventing crime

Question 4

action of restriction enzymes

Answer 4

cut DNA fragments at precise locations

Question 5

action of electrophoresis

Answer 5

seperate fragments by size

Question 6

action of probes

Answer 6

find particular DNA fragments

Question 7

action of ligase enzyme

Answer 7

join DNA fragments

Question 8

action of vectors

Answer 8

transport DNA into cells

Question 9

action of gene cloning

Answer 9

obtain multiple copies of gene

Question 10

restriction enzymes (endonuclease)

Answer 10

used to cut up DNA molecules at very precise recognition sites
‘molecular scalpels’

Question 11

recognition site

Answer 11

specific site for the restriction enzyme that can cut DNA at that point
cutting site

Question 12

sticky ends

Answer 12

restriction enzymes that cut leaving an overhang

Question 13

two different fragments cut by the same restriction enzyme have identical sticky ends and are able to join by what?

Answer 13

base paring

annealing

Question 14

blunt ends

Answer 14

restriction enzymes that cut leaving no overhang

able to join with any other blunt end fragment

Question 15

ligation

Answer 15

pieces of DNA are joined together using the enzyme DNA ligase

Question 16

DNA ligase

Answer 16

enzyme involved in the joining of DNA fragments

Question 17

recombinant DNA

Answer 17

DNA that has recombined from different sources by DNA ligase

Question 18

steps of ligation

Answer 18

2 pieces of DNA are cut using the same restriction enzyme
the 2 different DNA fragments are attracted to each other by weak hydrogen bonds
other end of the foreign DNA is attracted to the remaining sticky end of plasmid

Question 19

annealing

Answer 19

when 2 matching sticky ends com together and are joined by base pairing
forms linear or circular (plasmid)

Question 20

plasmid

Answer 20

circular fragment of DNA

present in many copies in bacteria cells

Question 21

gene cloning

Answer 21

process of making large quantities of desired piece of DNA once it has been isolated

Question 22

vector

Answer 22

self-replication DNA molecule used to transit a gene from one organism to another

Question 23

steps of gene cloning

Answer 23

gene of interest isolated from human
appropriate plasmid vector is isolated from bacteria
gene and plasmid treated with same restriction enzyme to produce identical sticky ends
cuts plasmid in one place, cuts DNA in many places (only one has specific gene)
DNA ligase used to bond sticky ends of plasmid and DNA, forming a recombinant DNA plasmid
introduced into bacterial cell and cell division occurs

Question 24

DNA amplification / PCR (polymerase chain reaction)

Answer 24

creates vast quantities of DNA identical to trace samples

artificial DNA replication

Question 25

DNA polymerase

Answer 25

enzyme that controls the process of DNA replication

Question 26

steps of PCR

Answer 26

target DNA is obtained
DNA is denatured to single stranded by heating for 5mins at 98
primers (mRNA) annealed to each DNA strand
sample cooled to 60
DNA polymerase binds to primers on each side of DNA
this enzyme synthesises a complementary strand of DNA using free nucleotides
after one cycle: 2 copies of original sample

Question 27

primers

Answer 27

short, single-stranded DNA or RNA sequences complementary to a part of a specific DNA fragment

Question 28

gel electrophoresis

Answer 28

used to seperate large molecules on basis of size and electric charge

Question 29

steps of gel electrophoresis

Answer 29

prepare: restriction digest: DNA cut into smaller pieces
DNA placed into wells and covered with buffer solution
molecules move towards electrode depending on charge
DNA negatively charged (phosphates)
smaller fragments go further down

Question 30

DNA profiling (fingerprinting)

Answer 30

technique for genetic analysis which identifies the variation found in the DNA of individuals
gel electrophoresis

Question 31

DNA probe

Answer 31

a small fragment of nucleic acid that is labeled with an enzyme, radioactive tag or fluorescent dye tag
work by binding to a specific sequence on DNA

Question 32

DNA probes may be used for

Answer 32

presence of specific alleles
approximate location of gene on chromosome
genetic fingerprint of a person (paternity testing)

Question 33

Transformation

Answer 33

using genetic engineering techniques, concerned with the movement of genes from one species to another

Question 34

transgenic organism

Answer 34

organism that develops from a cell into which foreign DNA has been introduced

Question 35

recombinant DNA technology

Answer 35

allows direct modification of an organisms genome

allows traits to be introduced

Question 36

transformation is used for:

Answer 36

crops
production of herbicide resistant plants
enhancement of livestock
treatment of human defects

Question 37

DNA sequencing

Answer 37

used to determine the nucleotide (base) sequence of DNA

Question 38

gene therapy

Answer 38

the application of gene technology to correct or replace defective genes
target cancer, treat genetic disorders, provide relief for infectious diseases
not inherited when on somatic cells