Chapter 5 - Exploring Genes and Genomes - part 1

Question 1

Southern blots are used to separate and identify

Answer 1

DNA.

Question 2

Northern blots are used to separate and identify

Answer 2

RNA.

Question 3

de novo meaning

Answer 3

from the beginning.

Question 4

Restriction enzymes

Answer 4

recognize specific base sequences in double helical DNA and cleave both strands of that duplex at specific places.

Question 5

Restriction enzymes are used to

Answer 5

cleave DNA molecules into specific fragments that are more readily analyzed and manipulated than the parent molecule.

Question 6

For most gels, the shorter the DNA fragment, the

Answer 6

farther the migration.

Question 7

Western blotting refers to a technique for

Answer 7

detecting a particular protein by staining with specific antibody.

Question 8

Stringency is

Answer 8

the required closeness of the match between primer and target.

Question 9

Polymorphism

Answer 9

Instances of genetic variation.

Question 10

RFLP stands for

Answer 10

restriction-fragment-length polymorphisms

Question 11

Vector

Answer 11

A DNA molecule that can replicate autonomously in an appropriate host organism.

Question 12

Vectors are designed to

Answer 12

enable the rapid, covalent insertion of DNA fragments of interest.

Question 13

Plasmids

Answer 13

Naturally occurring circles of DNA that act as accessory chromosomes in bacteria.

Question 14

A vector can be prepared for accepting a new DNA fragment by

Answer 14

cleaving it at a single specific site with a restriction enzyme

Question 15

DNA ligase catalyzes

Answer 15

the formation of a phosphodiester bond at a break in a DNA chain

Question 16

Cloning vectors are suitable for the

Answer 16

facile insertion and replication of a collection of DNA fragments

Question 17

Cloning vectors often feature a polylinker region that includes many

Answer 17

unique restriction enzymes within its sequence

Question 18

The polylinker region can be

Answer 18

cleaved with many different restriction enzymes providing great versatility in the DNA fragments that can be inserted

Question 19

Reporter genes encode

Answer 19

rapidly-detectable markers such as antibiotic-resistance enzymes or fluorescent proteins

Question 20

In blue-white screening, bacterial colonies will appear white when

Answer 20

DNA fragments are successfully inserted into the polylinker region

Question 21

In addition to polylinkers, expression vectors often contain

Answer 21

sequences flanking the cloning site that simplify the addition of fusion tags to the protein of interest

Question 22

In the lytic pathway of lambda phages, viral functions are

Answer 22

fully expressed, viral DNA and proteins are quickly produced and packaged into viral particles leading to the destruction of the host cell

Question 23

In the lysogenic pathway of lambda phages, the phage DNA becomes

Answer 23

inserted into the host-cell genome and can be replicated together with the host cell DNA for many generations, remaining inactive

Question 24

Lambda particles can only take up DNA measuring from _____ to _____ of the normal genome

Answer 24

78-105%

Question 25

To clone a gene that is present just once in an entire genome, two components must be available

Answer 25

1. A specific oligonucleotide probe for the gene of interest
2. A DNA library that can be screened rapidly

Question 26

For the human genome, a 99% probability of success using the genomic library requires screening about _______ _____ clones

Answer 26

500,000

Question 27

The key to forming complementary DNA is

Answer 27

the enzyme reverse transcriptase

Question 28

Complementary DNA molecules can be inserted into expression vectors to

Answer 28

enable the production of the corresponding protein of interest

Question 29

In expression cloning, clones of cDNA can be screened on the basis of

Answer 29

their capacity to direct the synthesis of a foreign protein in bacteria

Question 30

New genes can be constructed with designed properties by making what three kinds of directed changes?

Answer 30

1. deletions
2. insertions
3. substitutions

Question 31

Mutant proteins with single amino acid substitutions can be readily produced by

Answer 31

site-directed mutagenesis

Question 32

In cassette mutagenesis,

Answer 32

a variety of mutations including insertions, deletions, and multiple point mutations can be introduced into the gene of interest

Question 33

Inverse PCR is used to introduce

Answer 33

deletions into plasmid DNA

Question 34

Novel proteins can be created by splicing together

Answer 34

segments that encode domains that are not associated in nature