Chapter 18 - Genetic Engineering

Question 1

Genetic Engineering

Answer 1

Deliberate manipulation of DNA, using techniques in the laboratory to alter genes in organisms.

Question 2

Gene Cloning

Answer 2

Process by which a gene of interest can be replicated many times over.

Question 3

Step 1 of Gene Cloning

Answer 3

Isolate DNA of interest. ie Glowing gene found in jelly fish, isolate the sequence responsible for this.

Question 4

Cloning Vector

Answer 4

Typically a plasmid or virus, capable of independent replication that will stably carry the target DnA from one location to another

Question 5

Step 2 of Gene Cloning

Answer 5

Cut the DNA with restriction endonucleases

Question 6

endonucleases

Answer 6

Enzymes that recognize short sequences of DNA that are 4-8 bp long. They’re widespread in both bacteria and archaea.

Question 7

How to endonucleases read DNA?

Answer 7

Palindromic (meaning same on each DNA strand in the 5’ to 3’ direction)

Question 8

How do endonucleases cut DNA?

Answer 8

Some cut straight, many make staggered cuts, producing very short regions of single-stranded DNA.

Question 9

sticky ends

Answer 9

Short region of single-stranded DNA on each strand after being cut by endonucleases. Invaluable in molecule cloning since unpaired bases will recombine with any DNA having the complementary base sequence.

Question 10

Step 3 of Gene Cloning

Answer 10

Combine target and vector DNA - following cleavage of both types of DNA, the two types are then combined together with DNA ligase. Results in recombinant DNA.

Question 11

DNA Ligase

Answer 11

Enzyme that repairs the covalent bonds on sugar-phosphate backbone of DNA.

Question 12

Recombinant DNA

Answer 12

DNA molecules that contain the DNA from two or more sources, also known as chimeras

Question 13

Step 4 of Gene Cloning

Answer 13

Introduction of recombined molecule into host cell.

Question 14

Bacteria reintroduction

Answer 14

transformation is often easiest method, using competent cells to pick up the recombinant DNA.

Question 15

electroporation

Answer 15

Also can be used for reintroduction, where cells are exposed to brief pulse of high-voltage electricity causing the membrane to become temporarily permeable to DNA passage

Question 16

genomic library

Answer 16

Combination of both cells with new DNA and cells with the old DNA 0 must be screened to select appropriate clone

Question 17

shotgun cloning

Answer 17

If random fragments of DNA were originally used, can result in thousands of tens of thousands of clones to be screened

Question 18

Agrobacterium Tumefaciens

Answer 18

plant pathogen that causes tumor formation called crown gall disease. Contains plasmid known as Ti plasmid, which inserts bacterial DNA into host plan genome. Utilized by scientists to do genetic engineering of plants.

Question 19

TI

Answer 19

Tumor Inducing

Question 20

Gene Gun

Answer 20

Small metal particles coated with recombinant DNA, which as blasted at plan or animal tissue at high velocity. If DNA is transformed or taken up by cell’s DNA< the genes are expressed.

Question 21

Viral Vectors

Answer 21

Virulence genes from a virus can be removed and foreign DNA inserted, allowing the virus capsid to be used as a mechanism for shuttling genetic material into a plant or animal cell.

Question 22

Gel Electrophoresis

Answer 22

Technique commonly used to separate nucleic acid fragments based on size. Porous gel made of agarose with nucleic acid samples placed into wells. Electric current applied. Smallest particles will move fastest. Larger particles will move slower.

Question 23

Polymerase Chain Reaction (PCR)

Answer 23

Method used to copy or amplify DNA in vitro. Can yield billionfold copies of a single gene. Template DnA is mixed with ingredients (primers, nucleotides, polymerase. Steps include denaturing DNA, drop temp to allow primers to anneal, and then reheat to allow DNA polymerase to extend.

Question 24

Antisense RNA

Answer 24

ssRNA, complementary to mRNA that will code for a protein. Made as a way to control target genes. a way to prevent diseases that are caused by production of a particular protein.