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

Photosynthetic Diversity

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 Nitrogen Dioxide (NO2)

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

Fig 10.5

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)

Oxygen is dangerously reactiveIt is only maintained by constant input

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)

25.7/26.10

Changes in biosphere allowed further changes in life

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

10.06 The electromagnetic spectrum

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

26.1(6th)

1. Prokaryotes (“Monera”) ch27 single celled lack nucleusno organellesdiverse biochemistry

27.2

(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

Some CYANOBACTERIA can also fix nitrogen

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

Problem: why is there any carbon left in the atmosphere?

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

29.7

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 ch32-34- includes a lot of plant eaters (herbivores)- and herbivore eaters (predators)

3. Animalia- important pollinators & dispersers of plants

Ch 38

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

29.8/29.16

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)

29.13/29.12

Coal Age – Carboniferous 290-360 MYBP

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

Gymnosperms

Gymnosperms

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

END