Chapter 7.9

Question 1

Why can one type organism express the gene of another

Answer 1

Because all species use the same genetic code

Question 2

How do scientist take advantage of the fact that a lll species share the same genetic code

Answer 2

by coaxing cells to take up Recombinant Dna

Question 3

RECOMBINANT DNA

Answer 3

genetic material that has been spliced together from multiple organisms.

this is referred to as genetic engineering/ or genetically modified

Question 4

TRANSGENIC ORGANISM

Answer 4

one that receives recombinant DNA

Question 5

The 4 steps in creating a transgenic organism

Answer 5

1. Acquire source Dna
2. Select a cloning vector
3. Create recombinant dna
4. Insert the recombinant Dna into a recipient cell

Question 6

1. ACQUIRE SOURCE DNA

Answer 6

1. from a source cell ( bacteria, animal or Plant

Question 7

Why is it problematic if the source is a eukaryotic cell and the recipient is a prokaryote

Answer 7

Bacterial cells cannot remove introns from mRNA, so the DNA would encode a defective protein

Question 8

How is a DNA copy made from a copy of mRNA (REVERSE TRANSCRIPTION)

Answer 8

1. a mature mRNA molecule with its intron already removed, is isolated.
2. An enzyme called REVERSE TRANSCRIPTASE is used to create DNA copy of the mRNA.

Question 9

What is the importance of REVERSE TRANSCRIPTION in transgenic organism creation

Answer 9

When transferring a Eukaryotic cell to a bacteria : Bacterial cells cannot remove introns from mRNA, so the DNA would encode a defective protein. an mRNA with introns already removed is used to create DNA. this Dna ( cDNA) is now able to encode the eukaryotic protein within the bacteria

Question 10

2. CLONING VECTOR

Answer 10

a self-replicating genetic structure that will carry the source DNA into the recipient cell

Question 11

An example of a common CLONING VECTOR

Answer 11

1. PLASMIDS

2. Viruses ( they are modified so they can transport DNA but not a disease)

Question 12

PLASMID

Answer 12

are small circle of DNA separate from the cell’s chromosome.

Question 13

3. CREATE RECOMBINANT DNA

Answer 13

CREATE RECOMBINANT PLASMIDS

1. DNA fragments that can be spliced together are created by using RESTRICTION ENZYMES to cut DNA at specific bases
2. selected fragments are spliced together ( recombinant DNA) and are used to attach to plasmids

Question 14

RESTRICTION ENZYMES

what are their natural function

Answer 14

are proteins that cut double stranded DNA at a specific base sequence.

Their natural function is to protect bacteria by cutting up DNA from infecting viruses.

Question 15

4. INSERT THE RECOMBINANT DNA INTO A RECIPIENT CELL

Answer 15

1. bacteria cell wall is zapped with electricity creating a temporary hole that admits the DNA.
   or//
   “Gene guns” shoot DNA-coated pellets directly into the cells.

or//
packaged into liposomes that fuses withe the recipient ‘s membrane

or//
hitched to a virus that “infects’ the cell

Question 16

How is a transgenic animal crated since it is incapable of growing from an isolated cell ( like a plant)

Answer 16

by using viruses to introduce genes into fertilized egg. the organism that develops will carry the foreign genes in every cell.

Question 17

. What is recombinant DNA

Answer 17

Recombinant DNA is the combined DNA from 2 or more organism

Question 18

What are transgenic organisms, and how are they useful?

Answer 18

Transgenic organisms are organisms that contain recombinant DNA. They produce drugs and other useful chemicals, degrade pollutants, incorporate pesticides in their tissues, are models for medical research, and secrete human proteins.

Question 19

What are the steps in creating a recombinant plasmid?

Answer 19

The steps in creating a recombinant plasmid include:

• using restriction enzymes to cut out the gene sequence from donor DNA;
• cutting the plasmid with the same restriction enzymes;
• allowing the donor sequence to combine with the plasmid DNA.

Question 20

. How do bacteria, plant, and animal cells take up recombinant DNA

Answer 20

Bacteria, plant, and animal cells are sometimes induced to take up recombinant DNA by exposure to electricity. Scientists also make cells take up new DNA by shooting it into cells with gene guns, inserting it into liposomes, and inserting it as plasmids into bacteria that enter plant cells and inject the plasmids.