Ch 29: Working Plant. Poem, Source, LaporteCoMG, figs/anims/tables

A. Biology & Society: Maple Plant Sap (concentrated by evaporation) = syrup

1. 40 L sap = ~1 L syrup, early spring: tap into xylem?, fig 1, 2-3% sucrose.
   
2. I think is in living xylem & phloem, & leaks into the tap from local sapwood
   
3. xylem: water, inorganic nutrients (below) from soil > roots > shoots > leaves > stomata > air
   
phloem: water, CH2O + amino acids, what else, para 3? - phloem travels from source to sink

B. How Plants Acquire and Transport Nutrients: Good roots page, Farabee

3. Obtain nutrients from soil (water/soil if aquatic), light, & CO2 from air, fig. 2. 
   
4. 9 macro-nutrients: C,H,O, & N,P,K,Mg,Ca,S,  more, fig 5, fertilizer: usually N,P,K, (& Ca)
   
5. 7 micro-: Fe,B,Zn,Cu,Mn,Mo,Cl mostly in enzymes/cofactors,  more, Not Na+!
6. older leaves affected first, younger leaves affected first
   
7. Root hairs: fig. 6,7: epidermis: plasma membrane transports salts & water in > cell to cell > endodermis > xylem.
8. Fungi aid most plants absorb nutrients: mutualism, fig. 7, mycorrhizae: root hair + fungal filaments.
9. Nitrogen: natural: bacteria supply most: fig. 8: N fixing, ammonifying, & nitrifying (also done by lightning).
10. Legumes: N-fixing bacteria in root nodules, fig 9, mutualism.  In crop rotation: uses less N fertilizer.
11. 
    
Water rises in xylem:  because atmosphere SUCKS:  leaf transpiration, lab ex,

12. water cohesion & adhesion helps lift xylem sap, fig 10: roots produce little pressure
13. Guard cells: protect plant from deyhdration
    
14. animation control transpiration, fig 11: turgid > open > photosynthesis; flacid > closed > night/stress/dehydration.  
15. Photorespiration is an evolutionary relic: RuBisCO does not discriminate between CO2 & O2, so O2 can plug it up
16. Measure water potential,  water potential: soil to air,  detailed explanation,
    
17. 
    
18. Phloem carries sugar/amino acids from sources: leaf in summer, to sinks: where growing/storing fig 13.  
19. Sieve elements conduct phloem, companion cells load them, sugar sucks, water follows > pressure > flow.

REVIEW
1. Chernobyl accident scattered radiation on plants.  Mosses vulnerable, why? 
2. How can you test if radiation & mutations decrease with distance from the site?   
3. How can you measure the age of a tree without killing it?
4. Why may leaf stomata close by noon on a summer day?  
    How can you test your hypothesis?  What is the outcome of closure?
5.  Most common plant nutrient deficiency?
6. Define cohesion & adhesion

C. Plant Control Systems are regulated by environmental conditions like temperature & water availablility
The control systems determine what every part is doing: growing, flowering, seeding, fruiting, etc.
(Plants have no nerves; but a few can move bits fast: trap insects, sensitive plant.)

Five main plant hormones: each is made at one or more locations, & moves to the rest of the plant.
Each has various effects: depends on where it is, & which other hormones are present. 
The actions enable the plant to develop, grow, reproduce, & protect it when conditions are difficult.
So "everything general" about plant's growth & development is determined by these five hormones
E.g. as cells produced by apical meristem move away from that region,
they may: remain embryonic, or differentiate into one of three tissue types. 
The location of the cells, & hormones present determine what happens.

12. Three hormones promote growth & development: know Table 1 in textbook 
    
13. 1. Auxin: made in shoots' apical meristem: actions: embryo development, apical dominance, 
14. cell elongation, & phototropism: auxin moves to dark side, in roots may cause gravitropism, Farabee
15. used in rooting compound: makes cuttings produce roots, fig 19.  
16. Overdose: herbicide: kills broadleaf weeds by making shoots grow too much.
    
17. 2. Cytokinins: made in roots, stems & leaves: promote meristem mitosis everywhere, & differentiation into tissues
    
18. 3. Gibberellic acid made in shoot & root apical meristems: causes shoot cell division, elongation, fruiting, seed germination,
    
Overdose: fig 18, by heat or fungus: bolting, fungus on rice, at Purdue, turn bush bean into pole bean


19. Two hormones inhibit growth & development
    
20. 4. Abscisic Acid (ABA): hormone is secreted when plant is stressed: e.g. drought or winter. 
    
21. ABA causes bud dormancy, seed maturation, & blocks germination until removed, fig 19;
    
22. ABA closes leaf stomata in dehydration = drought. 
    
5. Etheylene: promotes fruit ripening & leaf drop (not ABA!), fig 16: fruit in a bag ripens due to ethylene

Plant Hormones: list on left, Kimball,  Farabee,  Wiki, Resource..

REVIEW p 652
1. Axillary bud: dormant or growing: depends on level of  ? moving down from shoot tip, & ? moving up from roots
2. How does ripening green bananas in a brown/plastic bag work?
3. Which of Mendel's pea varieties did not produce gibberellin?
4. Which two hormones regulate seed dormancy & germination.  How?

D. Response to Stimuli...how to break winter dormancy: big chill?

14. Phototropism & gravitropism (auxin?dose/reponse: fig 20), all tropisms
    
15. & thigmotropism, & value to plants.
16. To decide if to flower many plants measure day/night length, fig 21
    
17. Plants may be long-night or short-night > Photoperiodism: Phytochrome(r/fr).
18. Explanation & animation
    
19. Other plants are neutral about day/night duration.
20. Flowering: there is probably a sixth hormone, florigen

CHECKPOINT p 655
1. Why are tropisms called growth responses?
2. A long-night plant will not flower in the spring. 
    You try to induce it to flower by placing it briefly in the dark during the middle of the day
    Outcome?  Better solution?

E. Evolution Connection: The Interdependence of Living Organisms..crop technology lessons include flowers/fertilization..

16. (Flowering) plants depend upon other types of living organisms, resource: scroll to flower animation..interdependence..

Resources:  Selection,  more detailed,  another source,  hydroponics,  Arabidopsis,  more,

REVIEW FOR TEST ON 2/13: Ch 15 prokaryotes to end, 16, 28, & 29 (this), labs
Best to just read textbook chapters, learn main issues, skip details, do work at end
All Life Family trees: Berkeley,  Eukaryotes/Protists,  Wiki,  U Arizona,
Wiki: Kingdoms: Prokaryotes: Archaea, Bacteria, Eukaryotes: Protista, Fungi, Plants
Compare three domains.  Prokaryote: nutrition,  cell wall: gram stain: - / +

End of CH Q
CH 16.
Sustainable moon base: could/should bacteria be excluded?
Which organisms require O2?  Which do not?
Which existed frst?   How did they live?

CH 17.
Chernobyl accident radiation fallout was especially hard on mosses, what effects? & why mosses?
What was done do to prove this fungus is the largest living organism?

CH 28.
How to measure the age of a tree? 
Why may stomata in a leaf close at noon, when light is brightest?  If closed how to determine the reason?

CH 29. In some situations more & more N fertilizer has to be added each year just to maintain the same yield
Soil nitrogen is determined by various organisms & processes
Naturally these processes are in balance = homeostasis > a rise in the product inhibits its production
"The added fertilizer reduces natural N fixation in the soil"
Why might the N fertilizer reduce natural N fixation?
& how can you determine if this is true?
Homeostasis concept may apply to the earth as a whole: Gaia hypothesis, in mythology