GM Plants

Question 1

(1) As a result of genetic modification, these tomatoes produce a new substance which has health benefits and turns the tomatoes purple. Name this substance

Answer 1

flavonoids

Question 2

(1) What is inserted into the DNA of another plant to make it transgenic?

Answer 2

a gene from another species

Question 3

(6) Describe how Agrobacterium tumefaciens can be used to create transgenic plants.

Answer 3

genetic modification
• transferring a gene from one organism to another
• restriction enzymes to cut the gene out
• plasmids used to carry gene
• sticky ends to join complementary bases
• ligase to join the DNA

use of Agrobacterium
• Agrobacterium is a vector (for the gene)
• the Agrobacterium has a suitable gene added to it • example of a suitable gene eg drought resistance
/ insect resistance / larger yield / for flavonoids
• Agrobacterium naturally invades plant cells
• its DNA is incorporated into the plant’s DNA

production of plants
• plant sprayed with Agrobacterium
• crown gall (formed)
• crown gall is cut into small pieces

• leaf discs are incubated with Agrobacterium

• (crown gall tissue / leaf discs) grown in tissue culture
• explants
• grown into crops

Question 4

(4) Explain one advantage and one disadvantage of introducing this gene into crop plants.

Answer 4

crop produces a toxin that kills insects (that eat plant)(1) •so less damage by insect / increased crop yield (1)
cross pollination / fertilisation with other plants (species) (1) •producing weeds that contain the toxin(1)

Question 5

(3) Describe how scientists can use plant breeding programmes to produce maize
plants with larger cobs.

Answer 5

selection of individuals with
{favourable
characteristics/largest
cobs}/collect seeds from plants
with large cobs
(1)
cross breeding (of selected
individuals)/plant seeds together
(from maize with large cobs) (1)
selection of offspring (1)
repeat process over time (1)

Question 6

(2) Explain how the use of pesticides may benefit maize production.

Answer 6

reduce number of pests (1)
reduced damage to crop/maize
(1)
increased yield (1)

Question 7

(1) The microorganism used as a vector to produce transgenic plants is

Answer 7

Agrobacterium tumefaciens