U3 KA3

Question 1

What are weeds?

Answer 1

• plants that compete with crop plants, reducing productivity.

Question 2

What are annual weeds?

Answer 2

• weeds that complete a full life cycle in 1 year.
• eg. Annual Nettle.

Question 3

Give 4 properties of Annual Weeds.

Answer 3

• rapid growth.
• high seed output.
• short life-cycle.
• long-term seed vitality.

Question 4

What are perennial weeds?

Answer 4

• weeds that grow over many seasons

Question 5

Give 2 properties of perennial weeds.

Answer 5

• they have storage organs, allowing them to grow into other plants.
• vegetative reproduction.

Question 6

What do pests do?

Answer 6

• they damage crop plants, reducing productivity.

Question 7

What are the 3 groups of animals that contain pests?

Answer 7

• insects
• nematodes
• molluscs

Question 8

What is a pathogen?

Answer 8

• a bacterium, virus or other microorganism that can cause disease.

Question 9

How is plant disease caused?

Answer 9

• cause by fungi, bacteria or virus, often transmitted by invertebrates, damaging crop plants.

Question 10

What is cultural control?

Answer 10

• a preventative that follows traditional control methods.

Question 11

Give 6 examples of Cultural Control.

Answer 11

• Crop Rotation
• Cover Crop
• Destroying Crop Residue
• Ploughing
• Sowing
• Weeding

Question 12

What is Ploughing?

Answer 12

• the turning of the topsoil to uproot any underground storage organs.

Question 13

What is Crop Rotation?

Answer 13

• not planting the same crop in the same field every year.

Question 14

What is chemical control?

Answer 14

• use of pesticides to control pests, diseases or weeds, to improve crop yield.

Question 15

What is a selective herbicide?

Answer 15

• a pesticide that has a greater effect on certain plant species.

Question 16

What is a Systemic Herbicide?

Answer 16

• a pesticide that spreads through the vascular system of a weed, killing it, and preventing re-growth.

Question 17

What is a Systemic Insecticide?

Answer 17

• a pesticide that spreads through the vascular system of a plant, killing the pests that feed on it.

Question 18

What are the negatives of Chemical Control? (3)

Answer 18

• toxic to non-target species.
• creates persistence in the environment.
• toxins can bioaccumulate in food chains.

Question 19

What is Bioaccumulation?

Answer 19

• a build up of a chemical in an organism.

Question 20

What is Biomagnification?

Answer 20

• an increase in the concentration of a chemical moving between trophic levels.

Question 21

What is Biological Control?

Answer 21

• removal of a pest species by introducing a control agent that is a natural predator, parasite or pathogen of the pest.

Question 22

What the risks associated with biological control? (2)

Answer 22

• control organism may become an invasive species.
• the control organism may become a pathogen, parasite or predator to another species.

Question 23

What is integrated pest management?

Answer 23

• the combination of Biological, Chemical and Cultural control methods to control pests and diseases.