- (Plants) - Study Q's 10 - Plant Physiology

Front 1

1. What is the definition of a hormone?

Back 1

substance produced in 1 part of the body and transported to another where it causes physiological effects

Front 2

2. Name 3 major functions of Gibberellins.

Back 2

seed germination, fruit development, stem growth

Front 3

3. Describe the mechanism of seed germination involving gibberellins. What is the economic significance of this?

Back 3

Embryo releases hormone

Causes aleurone layer in seed coat to release enzymes: breaks down starch into sugars
Becomes nutrient for the seed

Used in alcohol production

Front 4

4. Why are gibberellins often sprayed onto seedless fruits?

Back 4

causes fruit development so it helps enlarge fruits

Front 5

5. What is "bolting" and what hormone functions in this process?

Back 5

Gibberellins; a quick elongation of a flowering stem

Front 6

6. Name 3 functions of the plant hormone auxin.

Back 6

phototropism, gravitropism, apical dominance

Front 7

7. What is phototropism?

Back 7

-movement toward light

Front 8

8. How is phototropism accomplished in plants?

Back 8

auxin concentrates on the dark side os a shoot, causes cells to elongate, pushes stem toward light

Front 9

9. What is gravitropism and how is it accomplished in plants?

Back 9

movement relative to gravity; auxin pushes the shoot towards light (same way as photo)

Front 10

10. How do roots and shoots function differently with respect to gravitropism?

Back 10

roots: positively gravitrophic

shoots: negatively gravitrophic

Front 11

11. How does auxin work to expand/elongate cells?

Back 11

loosens cellulose microfibrils, causes rapid expansion

Front 12

12. What is apical dominance and what controls it?

Back 12

-auxin inhibits growth of lateral branches--

Front 13

13. What is the function of "releasing" apical dominance?

Back 13

a damaged apical meristem stops auxin production, allows for growth of branches

Front 14

14. Name one function of cytokinins?

Back 14

balance of cytokinins & auxins regulates plant growth

Front 15

15. Name two functions of ethylene (as a plant hormone).

Back 15

fruit ripening, apical hook

Front 16

16. How is ethylene used commercially?

Back 16

sprayed on fruit to help ripen it

Front 17

17. What is an apical hook and where does it occur?

Back 17

? (12/21)

Front 18

18. What are phytochromes, what are the 2 chemical forms, and how are these forms induced?

Back 18

photoreceptor proteins:
Pr absorbs red light  Pfr
Pfr absorbs far red light  Pr

Front 19

19. What is a major function of phytochromes?

Back 19

induces germination (only Pfr form after exposure to red light)

Front 20

20. What is the name of the mechanism that explains water transport in plants?

Back 20

Transpiration Cohesion Tension Model

Front 21

21. What is the name of the mechanism that explains sugar transport in plants?

Back 21

Pressure Flow (from high concentration to low concentration)