Chapter 20

Question 1

recombinant DNA

Answer 1

nucleotide sequences from 2 different sources, often two species, are combined in vitro into the same DNA molecule

Question 2

genetic engineering

Answer 2

the direct manipulation of genes for pratical purposes

Question 3

biotechnology

Answer 3

the manipulation of organisms or their genetic components to make useful products

Question 4

DNA cloning

Answer 4

well defined segments of DNA in identical copies

Question 5

plasmids

Answer 5

small circular DNA molecules that replicate separately from the bacterial chromosome

Question 6

why are cloned genes useful?

Answer 6

to make copies of a particular gene and producing a protein product

Question 7

gene cloning

Answer 7

involves using bacteria to make multiple copies of a gene

• foreign DNA is inserted into plasmid, and then that plasmid is inserted into a bacterial cell
• reproduction in the bacterial cell results in cloning of the plasmid including the foreign DNA
• this results in the production of multiple copies of a single gene

Question 8

restriction enzymes

Answer 8

cut DNA molecules at specific DNA sequences called restriction sites

Question 9

restriction fragments

Answer 9

when a restriction enzyme makes many cuts this creates restriction fragments

Question 10

sticky ends

Answer 10

most useful restriction enzymes cut DNA in a staggered way making sticky ends

Question 11

DNA ligase

Answer 11

an enzyme that seals the bonds between restriction fragments

Question 12

cloning vector

Answer 12

the original plasmid

-can carry foreign DNA in a host cell and replicate there

Question 13

genomic library

Answer 13

the collection of recombinant vector clones produced by cloning DNA fragments from an entire genome

Question 14

bacterial artificial chromosome (BAC)

Answer 14

large plasmid that has been trimmed down and can carry a large DNA insert

Question 15

complementary DNA (cDNA)

Answer 15

made by cloning DNA made in vitro by reverse transcription of all the nRNA produced by a particular cell

Question 16

nucleic acid probe

Answer 16

a way to identify a gene of interest… has a sequence complementary to the gene being seeked..this process is called nucleic acid hybridization

Question 17

cloned genes can be expressed as protein in (bacteria or eukaryotic cells?)

Answer 17

BOTH

Question 18

expression vector

Answer 18

a cloning vector that contains a highly active bacterial promoter

Question 19

electroporation

Answer 19

applying brief electrical pulse to create temporary holes in the plasma membranes
-a method of introducing recombinant DNA into eukaryotic cells

Question 20

polymerase chain reaction (PCR)

Answer 20

can produce many copies of a specific target segment of DNA
-a 3 step cycle (heating, cooling, and replication) brings about a chain reaction that produces an exponentially growing population of identical DNA molecules

Question 21

Taq polymerase

Answer 21

a PCR that is very useful because it can work in very extreme temperatures and still produce copies of a specific target segment

Question 22

what does cloning allow researchers to do (3)

Answer 22

1. compare genes and alleles between individuals
2. locate gene expression in a body
3. determine the role of a gene in an organism

Question 23

gel electrophoresis

Answer 23

• analyzing and comparing genomes

- separates nucleic acids by size, electrical charge (goes from negative to positive)

Question 24

polymorphisms

Answer 24

variations in DNA sequence

Question 25

RFLPs (restriction fragment length polymorphisms)

Answer 25

sequence changes that alter restriction sites

-a variation in the length of restriction fragments produced by a given restriction enzyme in a sample of DNA.

Question 26

southern blotting

Answer 26

combines gel electrophoresis and DNA fragments with nucleic acid hybridization

Question 27

what is used to compare mRNA from different developmental stages

Answer 27

1. northern blotting

2. reverse transcriptase- polymerase chain reaction

Question 28

northern blotting

Answer 28

an adaptation of the Southern blot procedure used to detect specific sequences of RNA by hybridization with complementary DNA.

Question 29

reverse transcriptase polymerase chain (RT-PCR)

Answer 29

quicker and more sensitive because it requires less mRNA than Northern blotting

• added to mRNA to make cDNA, which serves as a template for PCR amplification of the gene of interest
• products are run on a gel and the mRNA of interest idnetified

Question 30

situ hybridization

Answer 30

uses flourescent dyes attached to probes to identify the location of a specific mRNAs in place in the intact organism

Question 31

DNA microarray assays

Answer 31

compare patterns of gene expression in different tissues, at different times, or under different conditions

Question 32

in vitro mutagenesis

Answer 32

use this, mutations are introduced into a clone gene, altering or destroying its function

Question 33

what are ways to determine gene function

Answer 33

1. disable gene and observe consequences
2. mutations with vitro mutagenesis then when mutated gene is returned to cell, the normal genes function might be determined by examining the mutants phenotype

Question 34

RNA interference

Answer 34

Synthetic double-stranded RNA molecules matching the sequence of a particular gene are
used to break down or block the gene’s mRNA

Question 35

SNPs (single nucleotide polymorphisms)

Answer 35

genetic markers

Question 36

totipotent cell

Answer 36

on that can generate a complete new organism

Question 37

stem cell

Answer 37

unspecialized cell that can reproduce itself indefinitely and differentiate into specialized cells of one or more types

Question 38

embryotic stem cells can make:

Answer 38

1. liver cells
2. nerve cells
3. blood cells

Question 39

adult stem cells

Answer 39

1. blood cells

Question 40

gene therapy

Answer 40

alteration of an afflicted individuals genes (very risky)

-vectors are used for delivery of genes into specific types of cells

Question 41

transgenic

Answer 41

made by introducing genes from one species into the genome of another animal
-these animals are pharmaceutical “factories” producers of large amounts of substances for medical uses

Question 42

genetic profile

Answer 42

individuals DNA sequence

Question 43

short tandem repeats

Answer 43

variations in the number of repeats of a specific DNA sequence

Question 44

Ti plasmid

Answer 44

most commonly used vector for introducing new genes into plant cells

Question 45

GMO

Answer 45

-putting pesticides on plants so animals dont eat them and thus can have a bigger output in product