Chapter 21: Gene Technology

Question 1

DNA probe

Answer 1

a section of DNA that is complimentary to a target gene that has a marker attached to it to make it identifiable

Question 2

recombinant DNA

Answer 2

Describes the DNA of two different organisms that have been combined - genes are isolated cloned and transferred into another organism

Question 3

What do you call organisms that have recombinant DNA?

Answer 3

transgenic or genetically-modified organism GMO

Question 4

Using DNA technology to make a certain protein for example requires 5 basic steps. What are these steps?

Answer 4

1. Isolation
   of the DNA fragments that have the gene for the desirable protein
2. Insertion
   of the DNA fragment into a vector
3. Transformation
   transfer of the DNA into a suitable host
4. Identification
   of the host cells that have successfully take up the gene
   by using gene markers
5. Growth/Cloning
   of the host cells that have the gene

Question 5

Why is it possible for the DNA of one organism to be transferred into another and for that DNA to be accepted and still function normally?

Answer 5

The genetic code is universal.
Making proteins is also universal because the mechanisms of transcription and translation are the same in all organisms

This is indirect evidence of evolution

Question 6

palindrome sequence

Answer 6

a sequence of bases that reads the same in the opposite direction

reading the bases from left to right on one strand gives the same sequence when the opposite complimentary strand is read right to left

Question 7

sticky ends

Answer 7

when restriction endonucleases cut a recognition site in a staggered fashion, leaving unpaired, exposed bases

Question 8

blunt ends

Answer 8

formed when restriction endonucleases cut a recognition site in a straight line

Question 9

Describe the process of using reverse transcriptase to produce a DNA fragment.

Answer 9

a host cell that already produces the desired protein is selected

these cells will have large quantities of the relevant mRNA so it is more easily extracted

reverse transcriptase is used to make DNA from mRNA

cDNA is produced by nucleotides complimentary to mRNA

DNA polymerase joins together complimentary nucleotides attracted to the cDNA template

To make the required double-stranded DNA

Question 10

restriction endonucleases

Answer 10

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Question 11

Describe the process of using reverse transcriptase to produce a DNA fragment.

Answer 11

a host cell that already produces the desired protein is selected

these cells will have large quantities of the relevant mRNA so it is more easily extracted

reverse transcriptase is used to make DNA from mRNA

cDNA is produced by nucleotides complimentary to mRNA

DNA polymerase joins together complimentary nucleotides attracted to the cDNA template

To make the required double-stranded DNA

Question 12

restriction endonucleases

Answer 12

enzymes that can cut a double stranded segment of DNA at a specific recognition site as the active site of the enzyme is complimentary only to that recognition site

Question 13

recognition sequence

Answer 13

a 6 base palindrome sequence found in the DNA of all species of organisms, just not in the same places

Question 14

DNA fragments that have been obtained need to be cloned. What are the 2 ways in which they can be cloned?

Answer 14

In vivo - by transferring the DNA fragment into a vector or host cell
In vitro - using polymerase chain reactions

Question 15

vector

Answer 15

used to transport DNA into a host cell

Question 16

Describe the process of using restriction endonucleases to produce a DNA fragment.

Answer 16

Restriction endonucleases are used to cut out fragments containing the desired gene