Plant physiology

What are 5 characters that might define a good model plant for understanding genetics and physiology 

1. Economic value - are cheaper

1. Small size - easier to store

1. Short generation time - can see results quicker

1. High fecundity - the ability to produce a lot of offspring

1. Easy to manipulate genetically 

        • Extras: resilience, change in morphology 

What are 3 features of cells that are distinctive and typical of plants 

1. 2 cell walls 

2. Chloroplasts

3. Vacuole

4. Plasmodesmata

What is the difference between apoplast and symplast?

5. Apoplast: this pathway involves the movement of water outside of protoplast cell wales from cell to cell via spaces in the cellulose cell walls 

6. Symplast: this pathway involves the movement of molecules through the cytoplasm from cell to cell via plasma membranes and plasmodesmata 

Which is a better system to conduct water?

7. Apoplast 

Which is a better system to conduct large bodies of water?

8. Symplast: it is more tightly regulated and specific, in apoplast they will spread everywhere and waste energy

What are the three major kinds of plant tissues and their functions?

9. Dermal tissue - provides protection through epidermis, cuticle, guard cells and root hairs.

10. Ground tissue - structural and mechanical support and metabolic processes 

11. Vascular tissue - functions in conduction of water and nutrients (xylem) and in conduction of sugars and signal molecules (phloem).

Describe the diversity of plants and plant physiology

12. How many species? 

    1. Angiosperms: 400,000  Gymnosperms: 1100 

13. What kind of diversity in growth forms?

    1. Trees, shrubs, herbs, climbers

14. What kind of diversity in physiology?

    1. Exhibit different metabolism such as C3, C4, CAM photosynthesis

    2. In nutrient and pigment concentrations, hormone sensitivity

    3. In all aspects of structure: wide variation in cell sizes in each tissue, leaf size and colors

15. What kind of diversity in adaptation to different habitats?

    1. Irrance habitats: plants thriving from <1% to 100% full daylight

    2. Moisture supplies: plants exist on chronically dry soil, on ever-wet soil, or submerged in water

    3. Temperature range: plants exist where temperature reaches <-40 C and greater than 40C

Give three reasons that plants need water & indicate which of the three reasons accounts for the bulk of water used

16. Transpiration: this accounts for the bulk of water being used. It cools the plants by dissipating heat energy via evaporation of water. Opens stomata to access CO2, but lose water as a side effect. (side effect of photosynthesis)

17. Plant growth: tissue expansion via turgor pressure, structural support

18. Photosynthesis: Insufficient water will close stomata and prevent photosynthesis. Water is also important to crop yields and cools the leaf.

Why is transpirational cooling effective?

19. The evaporation of water utilizes a high heat vaporization and a high specific heat. Thus, it takes a lot of energy to increase the temperature of water. This allows the plants to stay under bright sunlight and be a few degrees cooler than air.

 Capillary rise = (14.9 * 10-6 m2)/ radius

20. How high can water rise in cell wall pore capillaries (radius = 100nm)