Download - economic importance of plants
![Page 1: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/1.jpg)
economic importance of plants
• food— 80% human calories (stored starch) from 6 crops– wheat, rice, maize – potatoes, casava, sweet potatoes
• fiber, wood (lignified cell walls)– fabric, paper, building material, fuel
![Page 2: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/2.jpg)
economic importance of plants
• medicine (2ndary chemical compounds)– aspirin = synthetic version of
compound from willow– Table 30.1– 1/4 prescription medications--plant
produced (more efficient)
![Page 3: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/3.jpg)
Artemisia produces antimalarial compound in glandular hairs
Science Jan 15, 2010
![Page 4: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/4.jpg)
Plant nutrition
• autotrophs w/ chlplsts--PS pigments– chla & accessory pigments: chlb, carotenoids
• light energy from sun, C from CO2
• minerals N, P, K, Ca, Mg, S – (and 7 micronutrients)
• make sugar; store as starch• energy from breakdown of food
– mitochondria--cellular respiration (requires O2)
![Page 5: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/5.jpg)
ecological importance of plants
• ~290,000 sp. +• diverse habitats• nutrient cycling
![Page 6: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/6.jpg)
• base of terrestrial food chain (Fig 54.11)– primary producers
• energy transfer ~10% efficient – (Figs 55.9 & 10)– most goes to cellular respiration, waste-->
heat
![Page 7: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/7.jpg)
carbon cycle
Fig 55.14
C from air stored in organisms, fossils, soils
respiration,decomposition, burning
return to air
![Page 8: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/8.jpg)
CO2 and plants
w/extra CO2, plant growth increases but limited by other nutrients
growth affected by temp & precip plants may not be able to migrate fast enough, esp. w/ habitat fragmentation
![Page 9: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/9.jpg)
Fig 55.14
water cycle
H20 evap (pl. stomata) & retention
shade
fallen leaves—>humus soil holds H20
habitat for detritivores (decomposers)
![Page 10: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/10.jpg)
nitrogen cycle
Fig 55.14
prokaryotes convert N
plants absorb N, animals eat plants
plants retain N that would wash away
![Page 11: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/11.jpg)
eutrophication:
increased nutrients in waterphytoplankton & plants grow abundantly
respire at night (use up O2)aerobic prok degrade (use up O2)obligate aerobes die (dead zones)
Fig 55.18
![Page 12: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/12.jpg)
phosphorous cycle
Fig 55.14
P cycles between autotrophs (absorb it) & heterotrophs
or lost until geological processes return it
sticks to soil that is rich in organic matter
![Page 13: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/13.jpg)
Hubbard Brook Expts: studies of nutrient cycling
• isolated valleys, bedrock, drain indply• 60% H2O leaves, 40% evap through plants• internal cycling conserves nutrients• remove plants from one valley
– 30-40% increase water loss– minerals lost: Ca2+, K+, NO3
-
– conclusion: plants control nutrient cycling• acid rain dissolves Ca2+, affects biomass
– added Ca2+ improves plant health
![Page 14: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/14.jpg)
rates of nutrient cycling
dep. on temp, moisture, nutrients
faster at higher temps, enough H2O
slower if cold, too dry or too wet
![Page 15: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/15.jpg)
example:
peatlands cool & wet anaerobic
organic matter accumulates
CO2 stored
![Page 16: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/16.jpg)
sexual reproduction
• haploid: having 1 set of chromosomes
• diploid: having 2 sets of chromosomes
• polyploid: having >2 sets of chromosomes
![Page 17: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/17.jpg)
sexual reproduction
• mitosis: division of nucleus to form
2 nuclei w/same no of chromosomes of original nucleus
• meiosis: division of nucleus to form4 nuclei w/half no. of chromosomes of original nucleus
![Page 18: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/18.jpg)
sexual reproduction
• fertilization (syngamy): fusion of 2 gametes to form 1 zygote
• isogamy: gametes same form and size• anisogamy: gametes same form, different
size
• oogamy: large non-motile gamete (egg) & small motile gamete (sperm)
![Page 19: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/19.jpg)
Life cycle terms
• alternation of generations: life cycle with at least 2 multicellular phases that can be distinguished by reproductive cells and sometimes by morphology
• spore: a reproductive cell capable of growing into a new organism w/out fusing with another cell
![Page 20: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/20.jpg)
Life cycle terms
• sporophyte: multicellular spore-producing phase of organism with an alternation of generations
• gametophyte: multicellular gamete producing phase of organism with an alternation of generations
![Page 21: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/21.jpg)
Life cycle terms
• heteromorphic (“other form”) generations look different
• isomorphic (“same form”) generations look the same
• alternation of heteromorphic or isomorphic generations
![Page 22: economic importance of plants](https://reader036.vdocument.in/reader036/viewer/2022081415/56815295550346895dc0bcd1/html5/thumbnails/22.jpg)
2n
nmeiosis syngamy
zygote
gametes
sporophyte
spores
gametophyte
kelps, plantsFig 28.16
3 Life Cycles Fig 13.6
n
2n
zygote
ChlamydomonasFig 28.22
n
2n
gametes
humans
mitosis mitosis
mitosis