Post on 16-Mar-2020
BIO 152 Principles of Biology II
First half: Plants & Ecology
Instructor: Scott Gleeson
See Blackboard for syllabus & course information, etc.
Second half: Animal Biology Instructors: Robin Cooper (001)Phil Bonner (002)
Essentials (1st half):Lecture formatTwo exams (Sept 22, Oct 20) in class
mult. choice, non-cumulative, based on lectureMaterials posted on Blackboard/web
46, 47, 48, 49, 50
10:30am Exam #4 (Finals Week)RDec 17
50Muscle R10 27
49Sensory SystemsT826
48, 49The Nervous System R3 25
47Animal DevelopmentTDec 1 24
Thanksgiving Break, no classR26
46Animal ReproductionT24 23
40, 42, 44, 45
Examination # 3R19
46Animal ReproductionT17 22
45Hormones/ Chemical SignalsR12 21
44OsmoregulationT10 20
42Gas Exchange, OsmoregulationR5 19
42Gas Exchange, OsmoregulationTNov 3 18
42Gas Exchange R29 17
42Circulation T2716
40, 44 Homeostasis R22 15
37, 38, 39, 52
Examination #2 T20
40Animal Structure and FunctionR1514
52“ (last plant lecture)T1313
52Ecology R812
39“T611
39 Plant Responses ROct 1 10
38“T299
38Plant Reproduction R24 8
29, 30, 35, 36
Examination #1 T22
37Plant NutritionR17 7
36 “T15 6
36 Transport R10 5
35 “T8 4
35 Vascular Plant Structure R33
30 Flowering Plants TSept 1 2
29 Plant Diversity RAug. 27
1
Chapter Topic Day
Date Lect.
46, 47, 48, 49, 50
10:30am Exam #4 (Finals Week)RDec 17
50Muscle R10 27
49Sensory SystemsT826
48, 49The Nervous System R3 25
47Animal DevelopmentTDec 1 24
Thanksgiving Break, no classR26
46Animal ReproductionT24 23
40, 42, 44, 45
Examination # 3R19
46Animal ReproductionT17 22
45Hormones/ Chemical SignalsR12 21
44OsmoregulationT10 20
42Gas Exchange, OsmoregulationR5 19
42Gas Exchange, OsmoregulationTNov 3 18
42Gas Exchange R29 17
42Circulation T2716
40, 44 Homeostasis R22 15
37, 38, 39, 52
Examination #2 T20
40Animal Structure and FunctionR1514
52“ (last plant lecture)T1313
52Ecology R812
39“T611
39 Plant Responses ROct 1 10
38“T299
38Plant Reproduction R24 8
29, 30, 35, 36
Examination #1 T22
37Plant NutritionR17 7
36 “T15 6
36 Transport R10 5
35 “T8 4
35 Vascular Plant Structure R33
30 Flowering Plants TSept 1 2
29 Plant Diversity RAug. 27
1
Chapter Topic Day
Date Lect.
From the syllabus
BIO 192 – Supplemental Biology Workshop (BioExcel)
192-001 Mon 3-5 start Aug 31(rm 109)192-002 Mon 5-7 start Aug 31(rm 109)192-003 Wed 3-5 start Aug 26(rm 109)192-004 Wed 5-7 start Aug 26(rm 109)192-005 Tues 5-7 start Sept 1 (rm 108)192-006 Thur 5-7 start Aug 27(rm 108)
1 cr. P/F Contact: wscohen@uky.edu
Do you have a clicker?1. Yes2. No3. I have one but
didn’t bring it.4. Well, this is a
stupid question!
Course Outline (first half)
Photosynthetic DiversityVascular Plant Form and Function
How Plants WorkPlant Structure TransportNutritionReproductionEnvironmental Response
Ecology – terrestrial ecosystems & biomes
Percent Composition of Planetary Atmospheres
CO2 O2 N2
WHY?
Venus 96.5 trace 3.5
Mars 95 0.13 2.7
Earth 98 0.0 1.9(predicted)
Earth 0.03 21 79(observed)
Why is the earth’s atmosphere so aberrant??
The presence of life
How can such a humble thing as LIFE have such a dramatic effect on the chemistry of the atmosphere?
Two reasons
1. The biosphere is THIN
2. Biology IS Chemistry
Earth is LARGE but Biosphere THIN
Earth 8,000 miles in diameterOcean + atmosphere about 20 miles thick
20/8000 = 1/400if earth 40cm, biosphere 1mm
Consequence of this “thinness”- Region is relatively fragile & sensitive- Life (incl. Humans) can affect it
8,000
1. The Biosphere is THIN
Whole biosphere has been altered – atmosphere, climate, ocean chemistry & currents, even geology of earth’s crust
Global patterns of Carbon Monoxide (CO)
http://www.gsfc.nasa.gov/gsfc/earth/terra/co.htm
Key feature of life – ability to transformABIOTIC (non-life) into BIOTIC (life)
Today, most of this work is done by PLANTS, or more generally
AUTOTROPHS (Gk: auto = self, trophos = feeder)Heterotrophs (hetero = other) transform other life
Key plant chemistry – PHOTOSYNTHESIS
Light + CO2 + Water = more plant(sugar) + O2
See ch. 10 for details
2. Biology IS chemistry
Once established, life began to alter the earth (“biosphere”) itself
Because photosynthesis happens on a large scale, it can result in a change in the atmosphere.
Light + CO2 + Water = sugar + O2
Oxygen gas (O2) is created as a byproduct of photosynthesis, and carbon dioxide (CO2) is used up.
This change is detectable from space – due to the change in the spectral quality of reflected light. As a result, it has been predicted that there is NO LIFE on the other planets in the solar system.
Key indicator – are gases in chemical equilibrium or not?
Percent Composition of Planetary Atmospheres
CO2 O2 N2
Venus 96.5 trace 3.5
Mars 95 0.13 2.7
Earth 98 0.0 1.9(predicted)
Earth 0.03 21 79(w/ life)
Change in the atmosphere had many effects, including
1. High O2 allowed aerobic respiration (& multicellularity?) because O2 is highly reactive
2. O2 ionized to ozone (O3) in the upper atmosphere reduced ultraviolet radiation at the surface
3. Reduced CO2 – lowered global temperatures it is a major greenhouse gas
Human activities have been partially reversing 2&3 by1. producing chemicals that reduce ozone2. increasing atmospheric CO2
(fossil fuel burning and deforestation)
Major biochemical pathways and processes detailed in BIO 150:
Photosynthesis (ch. 10)
CO2 + H2O + light = sugar + O2
Respiration (ch. 9)
Sugar + O2 = Energy + CO2 + H2O
Notice the reciprocal nature of these two equations
10.5
9.17/9.16
Energy flows through the system (degraded to heat)Materials can cycle indefinitely (are re-used)
9.2
Photosynthesis and respiration transform non-life into life using material and energy. The relation between the two processes
suggest an important generalization about living systems
Currently, the rate of oxygen creationappears to balance oxygen utilization
Photosynthesis and respiration appear to be globally in balance.
Problem: if they are in balance, how to explain the atmospheric imbalance?
Viewed from space, much of the planet has a greenish appearance, due to the presence of photosynthesizers.
The Biosphere is thin and life (biochemistry) covers the globe
Global climate modelers refer to this green layer in the biosphere as the “green slime”
Why is this “slime” green? Why are plants green??
Light – the ultimate energy source for plantsWhat kind of energy is it?
Physicists tell us that light has characteristics of both waves (wavelength) and particles (photons)
Visible light (what our eyes see) is part of a larger spectrum of electromagnetic waves
The energy of light is determined by wavelength
hc E = energyE = ------ h = Planck’s constant
λ c = speed of lightλ = wavelength
The sun emits electromagnetic waves as a function of its temperature. Its heat results from nuclear fusion (H to He)
The sun emits electromagnetic waves as a function of its temperature. Its heat results from nuclear fusion (H to He)
Peak (intensity) wavelength of a radiating body (Wein’s law)
Max λ = 2.88 x 106 / T (oK) T = temp
Sun temperature 5750 oK
Sun’s max λ = (2.88 x 106)/5750 = 500 nm (green)
[aside: at origin of life, sun 25% cooler; max λ = 670nm – orange, but high CO2 and temp 23o C]
0
200
400
600
800
1000
1200
3000 4000 5000 6000 7000
Temperature (K)
Peak
Wav
elen
gth
Sun’s max λ = (2.88 x 106)/5750 = 500 nm (green)
Most of the energy of sunlight (approx 50%) is contained the wavelengths around green, so it “makes sense” to use it
In addition- wavelengths above 700nm too weak to energize electrons- wavelengths below 400nm considered damaging
(although plants could probably adapt – some bacteria do)
So – the visible light region (400-700 nm) is where almost all the usable solar energy is.
Do plants use it?
How do plants use light?
Light energy is obtained by the absorption of photons (light “particles”) by PIGMENTS
Photosynthetic pigment molecules includeChlorophyll a, b, cCarotenoidsPhycobilins
10.1010.3
10.09
Each pigment has its own ABSORPTION SPECTRUM
The rate of photosynthesis is also a function of wavelength as a result of the pigments –ACTION SPECTRUM
So, plants use light in the visible range where most energy is, but there is a dip in absorption in the green-yellow range. So that’s why plants are green – that light is not absorbed, so it is reflected (so we see it).
Ok, but this means lots of energy is going to waste – why don’t plants use it?
Maybe – a mistake? Historical accident? (some cyanobacteriahave phycobilins)
If plants were fully utilizing sunlight, they wouldn’t be green, but black. So, why plant’s are green is still a mystery.
2,3 - chlorophyll a,b4 - phycoerythrobilin5 – beta-carotene
What is a cyanobacteria?
Who photosynthesizes?
How are they related?
How did the present photosynthetic diversity evolve?
Photosynthetic Diversity
The huge advances in DNA sequencing have enhanced our ability to reconstruct the family tree of life – and suggested a need for major revisions in our classification
Fig. 26-21
Fungi
EUKARYA
Trypanosomes
Green algaeLand plants
Red algae
ForamsCiliates
Dinoflagellates
Diatoms
Animals
AmoebasCellular slime molds
Leishmania
Euglena
Green nonsulfur bacteriaThermophiles
Halophiles
Methanobacterium
Sulfolobus
ARCHAEA
COMMONANCESTOR
OF ALLLIFE
BACTERIA
(Plastids, includingchloroplasts)
Greensulfur bacteria
(Mitochondrion)
Cyanobacteria
ChlamydiaSpirochetes
Life is divided into three main branches - DOMAINS
Eukarya
Archaea
Bacteria
Fig 26.21
Fig. 26-21
Fungi
EUKARYA
Trypanosomes
Green algaeLand plants
Red algae
ForamsCiliates
Dinoflagellates
Diatoms
Animals
AmoebasCellular slime molds
Leishmania
Euglena
Green nonsulfur bacteriaThermophiles
Halophiles
Methanobacterium
Sulfolobus
ARCHAEA
COMMONANCESTOR
OF ALLLIFE
BACTERIA
(Plastids, includingchloroplasts)
Greensulfur bacteria
(Mitochondrion)
Cyanobacteria
ChlamydiaSpirochetes
Eukarya
Archaea
Bacteria
Fig 26.21
Types of photosynthesis exist throughout this tree
Did photosynthesis evolve independently this many times?
Kingdoms Domains
1. Prokaryotes 1a. Archaebacteria Archaea(“Monera”) 1b. Eubacteria Bacteria
2. Protista3. Animalia Eukarya4. Fungi5. Plantae
Peruse ch. 26-34 to review this diversity, we will review some aspects relevant to photosynthesis and plants – how might plants view this diversity? Beginning to “think like a plant”.
The traditional “Kingdom” system is still used for classification and teaching purposes (e.g, text organization) but does not fully reflect the structure of the tree of life as currently recognized.
What happened to Kingdoms??
Eukarya
(Prokaryotes)No sexual reproduction (meiosis) per se, but various modes of genetic exchange horizontal transmission
Many are plant pathogens
27.12/18.17
(Prokaryotes)Some are free living and photosynthetic, especially CYANOBACTERIA (“blue-green algae”)
contain chlorophyll a, ancestor of chloroplasts
27.14/27.10
“Extremophiles” tolerate high temperatures, acidity, alkalinity & salinity
Archea
Fig 27.17
Fig 27.1
Other forms of photosynthesis occur in prokaryotes
Sulfur Bacteria
Halophiles (Archea) Fig. 27-18e
Thiomargarita namibiensiscontaining sulfur wastes (LM)
0.5
µm
Use H2S instead of H2O
CO2 + H2O +light = CH2O + O2
CO2 + H2S + light = CH2O + S2
Don’t use CO2 or other carbon source
Make ATP and use directly
27.18
27.1
Other important activities of prokaryotes- symbiotic N-fixation with plants (nodules)- important decomposers - N-transformation
27.18/27.13
Fig. 28-03aG
reenalgae
Amoebozoans
Op
isthoko
ntsA
lveolates
Stramenop
iles
Diplomonads
Parabasalids
Euglenozoans
Dinoflagellates
ApicomplexansCiliates
Diatoms
Golden algae
Brown algae
Oomycetes
ExcavataC
hromalveolata
Rhizaria
Chlorarachniophytes
Forams
Radiolarians
Archaeplastida
Red algae
Chlorophytes
Charophyceans
Land plantsUn
ikonta
Slime molds
Gymnamoebas
Entamoebas
Nucleariids
Fungi
Choanoflagellates
Animals
Fig. 28-03g5 µm
Fig. 28-03h50 µm
Fig. 28-03i20 µm
Fig. 28-03j20 µm
50 µm
Fig. 28-03l100 µm
Excavata
Chromalveolata
Rhizaria
Archaeplastida
Unikonta
Eukaryotes- 5 Supergroups
Fig 23.03
DO NOT LEARN
2. Protista – the “rest” of the eukaryotes - single & multicellular ch28- Eukaryotes – true nucleus (containing DNA), organelles- Many are heterotrophs – highly diverse
(Protista)-includes true ALGAE (in two supergroups) – single and multicellular forms that are photosynthetic, and mainly aquatic (main “producers” in aquatic systems)
A. Unicellular algae- contain chloroplasts- chlorophyll a, b, & c
A. Unicellular algae - includes DIATOMS – important planktonic algae (open water) with specialized internal structures of silica that preserve well in the fossil record
A. Unicellular Algae. Another group, the Coccolithophores, create calcium carbonate casings
Cretaceous period (145-65 MYa) Latin creta = chalk
Deep sea burial creates limestone & chalk
Carbon buried, oxygen increases in atmosphere -imbalance
B. Multicellular algae – red, brown and green algae –“seaweeds”- various differentiated structures- attached to underwater substrate (not rooted)- complex food conducting systems
B. Multicellular algae - Diverse life cycles – sporophyte AND/OR gametophyte dominant
28.16/28.21 Laminaria(brown alga)
13.6/13.5
Alternation of Generations
Alternation between haploid (gametophyte) and diploid (sporophyte) multicellular phases
B. Multicellular algae - “true” plants (Kingdom Plantae) probably evolved from a common (single) fresh water green-algal ancestor. Share chlorophylls, other pigments, chloroplasts and cellulose
29.3/29.2
Chloroplasts are specialized organelles that do the photosynthesis in eukaryotes
Endosymbiosis and Photosynthesis
Eukaryotic organelles are a result of endosymbiosis
Fig 10.3
Fig. 25-9-4 Ancestral photosyntheticeukaryote
Photosyntheticprokaryote
Mitochondrion
Plastid
Nucleus
CytoplasmDNA
Plasma membrane
Endoplasmic reticulum
Nuclear envelope
Ancestralprokaryote
Aerobicheterotrophicprokaryote
Mitochondrion
Ancestralheterotrophiceukaryote
Fig 25.9
Free living photosynthetic cyanobacteria became incorporated into a heterotrophic eukaryote.
Prokaryotes were incorporated into larger (nucleated?) cells that became mitochondria and chloroplasts
Did photosynthesis evolve multiple times in eukaryotes?
Endosymbiosis and the evolution of the chloroplast
28.2/28.3
This may have happened more than once- red algae chloroplasts have phycobilin
In a fundamental sense, all photosynthesis is done by bacteria (and their descendants)
3. Animalia - includes CORALS, which for a symbiotic association with “zooxanthellae” which are themselves a symbiosis of a dinoflagellate (protista) and photosynthetic cyanobacteria(prokaryote).
4. Fungi (ch 31)- eukaryotic, diverse heterotrophs- unicellular (yeast) and multicelled (mushrooms)- with bacteria, the most important decomposers (nutrient
releasers) in terrestrial systems
4. Fungi
- important mycorrhizal fungi, the root symbionts that enhance nutrient and water uptake
- many fungi are plant pathogens
36.5
4. Fungi- include photosynthetic LICHENS – a symbiotic association of a fungus and a green algae. Fungus gets carbohydrates for photosynthesis of algae. Live on bare substrate (rock, bark), tolerate drying.
Fig. 26-21
Fungi
EUKARYA
Trypanosomes
Green algaeLand plants
Red algae
ForamsCiliates
Dinoflagellates
Diatoms
Animals
AmoebasCellular slime molds
Leishmania
Euglena
Green nonsulfur bacteriaThermophiles
Halophiles
Methanobacterium
Sulfolobus
ARCHAEA
COMMONANCESTOR
OF ALLLIFE
BACTERIA
(Plastids, includingchloroplasts)
Greensulfur bacteria
(Mitochondrion)
Cyanobacteria
ChlamydiaSpirochetes
Eukarya
Archaea
Bacteria
Fig 26.21
Types of photosynthesis exist throughout this tree
Did photosynthesis evolve independently this many times?In bacteria, maybe yes, eukaryotes, no.
5. Plantae (ch. 29&30)A. Bryophytes (‘non-
vascular’ plants)B. Vascular Plants1. Seedless vascular
plants 2. Seed plants
a. Gymnospermsb. Angiosperms
(monocots, dicots)
29.7/29.1
Bryophytes- Includes mosses, liverworts and hornworts- generally small, similarities w/ green algae and
vascular plants- chlorophylls, cellulose, leaf cuticle, some food &
water conducting tissues
Bryophytes - life cycle shows alternation of generations, with the GAMETOPHYTE (haploid) the dominant generation and the sporophyte reduced to a dependent reproductive structure
Seedless Vascular Plants- Living groups include FERNS, also horsetails (Equisetum)
and Lycopods (or Lycophytes), all found in KY.
Seedless Vascular Plants – have vasculature- Important in fossil record – as far back as 430 million years (MY)- includes large plants, eg Tree Ferns – tree forms
common in past (coal age)- alternation of generations – SPOROPHYTE
(diploid) dominant- homosporous (one size spore), not generally
heterosporous (micro and mega spores)
2007 DOE annual report
http://www.eia.doe.gov/oiaf/ieo/oil.html
How long will petroleum supplies last?
Seed plants – main subject of courseA. Gymnosperms
(conifers, cycads, etc.)B. Angiosperms
(flowering plants)- dominant terrestrial
plants- vascular tissue, seeds,
sporophyte dominant, heterosporous
Evolutionary Trends in Plants
1. Shift to sporophyte dominance
2. Adaptation to land (drought resistance and support)- cuticle, stomates- wood, lignin- vascular tissue- seeds
3. Gamete dispersalwater => wind => animals