Plant responses

Question 1

Name 5 types of plant hormones

Answer 1

Gibberellins
Ethene
Abscisic acid (ABA)
Auxins (IAA)
Cytokinins

Question 2

Auxins (IAA)

Answer 2

Promote cell elongation
Inhibit growth of side shoots (lateral buds)
Inhibits leaf abscission

Question 3

Gibberellins

Answer 3

Promote seed germination and growth of stems

Question 4

Ethene

Answer 4

Fruit ripening

Question 5

Abscisic Acid (ABA)

Answer 5

Inhibits seed germination and growth
Causes stomatal closure when the plant is stressed by low water availability

Question 6

Cytokinins

Answer 6

Cell division
Delay leaf senescence
Overcome apical dominance
Promote cell expansion

Question 7

What is apical dominance?

Answer 7

Growth of plant from the apical shoot first the from the lateral buds later

Question 8

What type of pathogen causes TMV (Tobacco Mosaic Virus)?

Answer 8

Virus

Question 9

What are the symptoms of Tobacco Mosaic Virus?

Answer 9

Mottling and discoloration of leaves, stunted growth due to reduced photosynthesis

Question 10

How is TMV spread?

Answer 10

Direct contact and through contaminated tools

Question 11

What type of pathogen causes Rose Black Spot?

Answer 11

Fungus

Question 12

What are the symptoms of Rose Black Spot?

Answer 12

Purple or black spots on leaves, yellowing leaves, reduced growth due to less photosynthesis

Question 13

How is Rose Black Spot spread?

Answer 13

Water (rain splash), wind, contaminated tools

Question 14

How can Rose Black Spot be controlled?

Answer 14

Fungicides, removing and destroying infected leaves

Question 15

What type of pathogen causes Crown Gall disease?

Answer 15

Bacteria

Question 16

What are the symptoms of Crown Gall?

Answer 16

Tumour-like swellings (galls) usually near the root or stem

Question 17

How is Crown Gall spread?

Answer 17

Through soil, contaminated tools, or infected plants

Question 18

What type of pathogen causes Late Blight in potatoes and tomatoes?

Answer 18

Protist (Phytophthora infestans)

Question 19

What are the symptoms of Late Blight?

Answer 19

Brown patches on leaves, white fuzzy growth under leaves, rotting tubers

Question 20

How is Late Blight spread?

Answer 20

Water and wind (especially in wet conditions)

Question 21

Name a general physical defence in plants against pathogens.

Answer 21

Waxy cuticle, cell walls, bark

Question 22

Name a general chemical defence in plants against pathogens.

Answer 22

Antimicrobial compounds, enzymes like chitinase or glucanase

Question 23

How can farmers prevent the spread of plant diseases?

Answer 23

Crop rotation, resistant varieties, disinfecting tools, controlling vectors