Genetic Engineering And Cloning

Question 1

What is a transgenic organism ?

Answer 1

An organism which have received genes from another species

Question 2

What does genetic engineering involve ?

Answer 2

Involves transferring genes from one organism to another-often into a totally unrelated species

Question 3

What is a vector ?

Answer 3

Means of transferring a gene

Question 4

What are plasmids ?

Answer 4

Small circular pieces of DNA in the bacteria in addition to the main loop of DNA

Question 5

What do restriction enzymes do ?

Answer 5

They cut DNA at specific points

Question 6

What does ligase enzyme do ?

Answer 6

Enzymes that join together ends of DNA

Question 7

Give an example of a vector

Answer 7

Plasmid

Question 8

Describe genetic engineering using diabetes as an example

Answer 8

• firstly human insulin gene must be located and isolated
• The gene is then cut from the rest of the chromosome using a special enzyme called a DNA restriction enzyme
• A plasmid is extracted from the bacterium. The plasmid is then cut with the same restriction enzyme
• The human insulin gene is then attached to the plasmid using a DNA ligase enzyme
• The plasmid is then reinserted into the bacterium. The bacterium is now transgenic

Question 9

How do you manufacture large amounts of transgenic bacteria ? Use human insulin as an example

Answer 9

• The transgenic bacteria are then placed into a fermenter in order to increase number
• if the bacteria have enough nutrients and I kept at optimum conditions they will begin to produce human insulin
• The insulin released by the bacteria is then collected and distributed

Question 10

Why can plasmids be modified without killing the bacterium ?

Answer 10

Plasmids usually contain non-essential genes

Question 11

Why is it harder to genetically modify a plant ?

Answer 11

Because there are billions of cells in plants and each cell must receive the new gene

Question 12

How do you genetically modify a plant ?

Answer 12

• introduce the new gene or genes into plant cells

* producing whole plants from just a few cells

Question 13

What are you advantages of genetic engineering

Answer 13

• more precise method than selective breeding
• higher crop yield/better food quality
• disease resistant/ pest resistant
• less pesticide/herbicide used so less pollution

Question 14

Disadvantages of genetic engineering

Answer 14

• Not excepted by public
• long-term affects unknown
• May affect food chains or environment
• reduces variation

Question 15

What is artificial propagation?

Answer 15

Taking cuttings from leaves, roots or stands

Question 16

What is the method of cloning plants ?

Answer 16

Micropropagation

Question 17

Descibe micropropagation

Answer 17

• A small section called an explant is cut from the desired plant and grows into a small ball of cells called a callus
• Single cells are then taken from the callus, and then grown into an individual cloned plant
• if the plant has the desired features so will its offspring

Question 18

Why is micro propagation useful ?

Answer 18

It is useful for plants that are difficult to propagate by seeds or cuttings

Question 19

What does propagate mean ?

Answer 19

Produce

Question 20

Describe mammal cloning

Answer 20

• A cell is removed from the udder of a donor sheep
• The DNA is extracted
• an egg cell is taken from another donor sheep
• the nucleus is removed to form a ‘de-nucleated’ egg
• the DNA and egg are fused by electric shock
• the fused cell is then given another shock
• then the fused cell begins to divide to form an embryo
• The embryo is implanted into the uterus of a surrogate sheep