Biology- Chapter 12: DNA Technology and Genomics

studied byStudied by 8 people
5.0(1)
get a hint
hint

What is the average amount of DNA that is similar between humans?

1 / 88

encourage image

There's no tags or description

Looks like no one added any tags here yet for you.

89 Terms

1

What is the average amount of DNA that is similar between humans?

99.9%

New cards
2

How much of human’s DNA is noncoding?

97%

New cards
3

What is noncoding DNA made up of?

  • gene control sequences (ex: promoters)

  • introns

  • DNA located between repetitive DNA sequences

New cards
4

Where are the repeated DNA sequences found?

at the centromeres and the end of the chromosomes

New cards
5

What are the steps in DNA identification?

  • copying DNA

  • cutting DNA

  • sorting DNA by size

  • comparing DNA

New cards
6

What method is used when the source of DNA is scanty, impure, or in a partially degraded state?

the polymerase chain reaction (PCR) to prepare large quantities of a particular gene

New cards
7

What does the PCR method involve?

using short DNA sequences called primers to select the portion of the genome to be amplified

New cards
8

What are automated PCR machines called?

thermocyclers

New cards
9

how many molecules can the thermocycler produce in a few hours?

100 billion

New cards
10

PCR cannot replace gene cloning in cells when ___ ?

large amounts of DNA are needed

New cards
11

What is the DNA sample mixed with?

a heat tolerant DNA replication enzyme (DNA polymerase), DNA nucleotides, and primers that are complementary to the ends of the DNA fragment that is to be copied.

New cards
12

What is needed to start replication?

primers

New cards
13

This solution is exposed to what?

cycles of heating (to separate the DNA strands) and cooling

New cards
14

What enzyme can withstand the heat of each cycle?

the unusual DNA polymerase

New cards
15

How do scientists generate millions of copies of a single DNA fragment?

they choose a DNA fragment to copy and design primers that will bind to both ends of the fragment. DNA polymerase copies the segment between the two primers.

<p>they choose a DNA fragment to copy and design primers that will bind to both ends of the fragment. DNA polymerase copies the segment between the two primers.</p>
New cards
16

What are restriction enzymes?

they cut DNA at specific sequences

New cards
17

How long of a DNA sequence do the restriction fragments recognize?

4-8 nucleotides long

New cards
18

What are restriction fragments?

pieces of DNA produced from the restriction enzymes cutting it

New cards
19

What are “sticky ends”

2 double-stranded DNA fragments with single- stranded overhanging ends

<p>2 double-stranded DNA fragments with single- stranded overhanging ends</p>
New cards
20

Sticky ends DNA restriction fragments from ?

different sources

New cards
21

How do you add a piece of DNA from another source?

by cutting it using the same restriction enzyme

New cards
22

What does gel electrophoresis do?

it sorts DNA molecules by size

New cards
23

How does gel electrophoresis separate nucleic acids or proteins?

it uses a gel (a thin slab of jellylike material) as a molecular sieve

New cards
24

On what basis are the nucleic acids or proteins seperated?

size or electrical charge

New cards
25

How many steps are there to separate DNA in different mixtures?

7

New cards
26

What is the first step?

Restriction enzymes are used to prepare DNA fragments in each mixture

New cards
27

What is the second step?

A sample of each mixture is placed in a well at one end of a flat, rectangular agar gel slab

New cards
28

What is the third step?

A negatively charged electrode from a power supply is attached near the DNA-containing end of the gel, and a positive electrode is attached near the other end.

New cards
29

What is the fourth step?

the DNA molecules all travel through the gel toward the positive pole.

New cards
30

Are DNA molecules negatively charged?

yes

  • because of their phosphate groups

New cards
31

What is the fifth step?

As they move, the polymer fibers within the gel slows down the movement of the longer molecules more than it does shorter ones, separating them by length.

New cards
32

What is the sixth step?

After about 1⁄2 hour the electrodes are disconnected

New cards
33

What is the seventh step?

gel electrophoresis separates a mixture of DNA molecules into bands

<p>gel electrophoresis separates a mixture of DNA molecules into bands</p>
New cards
34

Are these bands of DNA the same length?

yes

  • the shorter molecules are towards the bottom

New cards
35

What are restriction fragment length polymorphisms (RFLPs)?

The differences in restriction fragments produced in this way

New cards
36

How many base pairs are different between two people?

3 million

New cards
37

What does electrophoresis allow us to see?

Similarities as well as differences between

  1. mixtures of restriction fragments belonging to the same individual

  2. the base sequences in DNA from two individuals.

New cards
38

How do you permanently preserve DNA fragments that are isolated by gel electrophoresis?

the pieces of DNA are transferred or ‘blotted’ out of the fragile gel onto a nylon membrane

New cards
39

How many steps are there to make a DNA fingerprint?

5

New cards
40

What is the first step?

A positively charged nylon membrane is placed over the gel and the negatively charged DNA fragments are transferred to membrane

New cards
41

What is the second step?

DNA is then ‘unzipped’ to produce single strands of DNA

New cards
42

What is the third step?

Biologists incubate the nylon membrane with radioactive probes. They can prepare a nucleic acid probe complementary to the DNA of interest and label it radioactively.

New cards
43

What is the fourth step?

A sheet of X-ray film placed over the gel will be exposed only where the desired DNA is on the gel.

New cards
44

What is a fingerprint?

The resulting pattern of bands

New cards
45

What is the fifth step?

To compare two or more different DNA fingerprints the different DNA samples are run side-by-side on the same electrophoresis gel

New cards
46

What are probes?

small fragments of minisatellite DNA tagged with radioactive phosphorous

New cards
47

When can the information be used to synthesize a short single strand of DNA with the complementary sequence?

When at least part of the nucleotide sequence of a gene is already known or can be guessed

New cards
48

What is the DNA labeled with?

a radioactive isotope or fluorescent dye

New cards
49

What is a nucleic acid probe?

This labeled, complementary single-stranded nucleic acid molecule

New cards
50

What is n.a.p. used for?

to find a specific gene or other nucleotide sequence within a mass of DNA

New cards
51

What do the probes hydrogen bond to?

the complementary sequence in the targeted DNA

New cards
52

What is this method used for?

detecting genes/specific DNA pieces depend on base pairing between the gene/DNA piece and a complementary single strand sequence on another nucleic acid molecule, either DNA or RNA.

New cards
53

What can happen once the researcher identifies a colony carrying the desired gene?

the cells can be grown further and the gene of interest (and/or its protein product) isolated in large amounts

New cards
54

What are minisatellites?

short sequences (10-60 base pairs long) of repetitive DNA that show greater variation from one person to the next than other parts of the genome

New cards
55

What is this variation exhibited in?

stutters or VNTRs

New cards
56

How many VNTR loci does DNA fingerprinting usually compare?

5-13

New cards
57

DNA fingerprinting simultaneously does what?

detects lots of minisatellites in the genome to produce a pattern unique to an individual

New cards
58

What are the odds that 2 people will share a DNA profile produced by 13 VNTR loci?

1 in a 100 billion

New cards
59

What does VNTR stand for?

variable number tandem repeats

New cards
60

What are length polymorphisms?

The non-coding DNA segments that vary in their length

New cards
61

What are some length polymorphisms made out of?

short repeating sequences of DNA nucleotides

New cards
62

What are VNTRs?

The nucleotides that repeat few or many times in tandem (one after another) in length polymorphisms

New cards
63

Is the amount of tandam repeats in a specific loci in DNA the same for everyone?

no, that’s why it is used for DNA identification

New cards
64

What does recombinant DNA technology do?

combines genes from different sources–even different species–into a single DNA molecule

New cards
65

How do researchers create recombinant DNA?

by inserting desired genes into plasmids

<p>by inserting desired genes into plasmids</p>
New cards
66

What are plasmids?

small, circular DNA molecules that replicate separately from the much larger bacterial chromosome

<p>small, circular DNA molecules that replicate separately from the much larger bacterial chromosome</p>
New cards
67

Are plasmids required for cell reproduction or growth?

no

New cards
68

What genes do plasmids carry?

genes that cause the bacterium to cause diseases or provide resistance against antibiotics.

New cards
69

What happens when DNA from another source is introduced to the plasmid?

they hydrogen bond with the plasmid DNA

New cards
70

How are the bonds made permanent?

DNA ligase forms covalent bonds between adjacent nucleotides

New cards
71

How many times is the plasmid cleaved?

one

New cards
72

the restriction enzymes creates sticky ends on what?

both the human DNA fragments and the plasmid

New cards
73

What is transformation?

A process by which bacteria take up DNA from the surrounding

New cards
74

The bacteria reproduces to produce what?

a clone of cells

New cards
75

How can cloned genes be used?

directly or to manufacture protein products

New cards
76

What is a cloning vector?

they copy genes and move them from one organism to the next

New cards
77

Can plasmids be used as cloning vectors?

yes

New cards
78

the restrction enzyme makes ___ of human DNA fragments

millions

New cards
79

What is the genomic library?

The entire collection of all the cloned DNA fragments from a genome

New cards
80

What are vectors?

short pieces of DNA that are capable of replicating on their own when inside a cell

  • they’re used for cloning

  • can be bacterial plasmids or phages

New cards
81

How is a phage used?

The DNA fragments are inserted into phage DNA molecules. The recombinant phage DNA can then be introduced into a bacterial cell through the normal infection process.

New cards
82

What happens to the phage inside the cell?

The phage DNA replicates and produces new phage particles, each carrying the foreign DNA. A collection of phage clones can constitute a second type of genomic library.

New cards
83

How do they identify the clone with the desired gene?

  • with testing the protein product or

  • viewing it under UV light or exposing it to photographic film, the probe glows and reveals its location.

New cards
84

How does reverse transcriptase help make cloned genes?

it makes complementary DNA which is shorter due to the lack of introns

New cards
85

What are cDNA libraries used for?

studying genes responsible for specific functions in a specific cell

New cards
86

What is the Human Genome Project?

an effort to map the human genome in total detail by determining the entire nucleotide sequence of human DNA

New cards
87

What are bacteria used for?

to manufacture protein products on a large scale because plasmids and phages are readily available and can be grown rapidly and cheaply

New cards
88

What are sheep cells used for?

they add glycoproteins to the initial ones made in bacteria

New cards
89

What is a GMO?

an organism that has acquired 1 or more genes by artificial means rather than through normal breeding methods

New cards

Explore top notes

note Note
studied byStudied by 22 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 10 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 17 people
Updated ... ago
5.0 Stars(2)
note Note
studied byStudied by 22 people
Updated ... ago
5.0 Stars(3)
note Note
studied byStudied by 3 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 104 people
Updated ... ago
5.0 Stars(3)
note Note
studied byStudied by 136 people
Updated ... ago
4.5 Stars(2)

Explore top flashcards

flashcards Flashcard59 terms
studied byStudied by 16 people
Updated ... ago
5.0 Stars(2)
flashcards Flashcard20 terms
studied byStudied by 31 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard669 terms
studied byStudied by 23 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard138 terms
studied byStudied by 5 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard28 terms
studied byStudied by 5 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard204 terms
studied byStudied by 7 people
Updated ... ago
4.0 Stars(1)
flashcards Flashcard36 terms
studied byStudied by 42 people
Updated ... ago
5.0 Stars(3)
flashcards Flashcard70 terms
studied byStudied by 38 people
Updated ... ago
5.0 Stars(1)