Today’s Plan: 4/12/10

Bellwork: Set up lab(15 mins) Finish AP Lab 11 (45 mins) Behavior notes (the rest of class)

Today’s Plan: 4/13/2010

Bellwork: Finish Plant Behaviors (15 mins)

Symmetry and tissue layers stations (45 mins)

Animal Behavior notes (the rest of class)

Pack/Wrap-up (last few mins of class)

Today’s Plan: 4/14/2010

Bellwork: Go over plans (10 mins) Finish Symmetry and tissues(40 mins) Notes, continued (the rest of class)

Today’s Plan: 4/19/2010

Check-in with animals progress (5 mins)

Finish Behavior notes (15 mins) Finish invertebrates/begin

vertebrates? (40 mins) Notes (the rest of class) Pack/Wrap-up (last few mins of class)

Today’s Plan: 11/12/09

Finish Behavior notes (20 mins) Finish Vertebrates (40 mins) Animals Notes (the rest of class)

Today’s Plan: 4/20/09

Bellwork: Invertebrate activities (20 mins)

Vertebrate activities (40 mins) Notes (the rest of class)

Today’s Plan: 4/21/09

Finish Beh. Notes (15 mins) Finish Vertebrates and chart (45

mins) Go over animals (the rest of class)

Plant Regulation and Behavior Plants use hormones to regulate function,

since they lack a nervous system There are a variety of hormones to control

every plant response or to regulate all of the plant’s functions Growth-auxin, cytokinins, and gibberellins Apical dominance-cytokinins Cell division and differentiation-cytokinins Germination and fruit growth-giberellins Leaf dropping (abscission)-abscissic acid Fruit ripening-ethylene

Figure 39-33-Table 39-2-1

Figure 39-33-Table 39-2-2

Figure 39-33-Table 39-2-3

Figure 39-26

PLANT TISSUE CULTURE

1. Start with pieceof plant tissue.

2. Callus grows. 3. Roots form. 4. Shoots form.

Figure 39-33

LEAF SENESCENCE AND ABSCISSION

Healthy leaf

Abscission zone

Age, drought, temperature,day length, etc. reduceauxin production from leaf

Senescent leaf

1. High auxin: Cells in abscissionzone are insensitive to ethylene. Leaf functions normally.

2. Low auxin: Cells in abscissionzone become more sensitive toethylene, leading to leaf senescence.

Abscised leaf

3. Leaf detaches at theabscission zone.

A protective layer hasformed to seal stemwhere leaf was attached

Figure 39-32

Apical Dominance Controlled by an interaction of auxin and

cytokinin Auxin produced at the terminal bud

supresses the axillary buds, but decreases in concentration as it moves down the shoot.

Cytokinins coming up from the root counteract the auxins in the stem, causing the lower axillary buds to develop

Figure 39-23

Apical meristem intact Apical meristem cut off

Lateralshoots

Figure 39-24

Apical end (toward shoot)G

rad

ien

t o

f au

xin

co

nce

ntr

atio

n

Basal end (toward root)

2H+

Auxin

Auxin

Cotransportersat top of cellsbring auxin in

Some auxinmolecules aredestroyed byenzymes asthey travel down

Carrier proteinsat bottom of cellssend auxin out

How do hormones work?

Usually, there’s a signal transduction pathway involved

Figure 39-1 STEPS IN INFORMATION PROCESSING

External stimuluson receptor cell

Internalsignal

Cell-cellsignal

Internalsignal

1. Receptor cellperceives externalstimulus andtransduces theinformation to aninternal signal.

2. A hormone(cell-cell signal)released by thereceptor cell travelsthroughout the body.

3. Receptor cellsreceive the hormonal(cell-cell) signal,transduce it to aninternal signal, andchange activity.

Figure 39-2SIGNAL TRANSDUCTION

Cell wall1. Signal

2. Receptor protein changesin response to signal.

Cell membrane

3. Receptor or associated proteincatalyzes phosphorylation reaction.

ATP

ATP

ATP

ATP

ADP

ADP

ADP

ADP

4. Phosphorylatedprotein triggersphosphorylationcascade (left)…

…OR release ofsecond messenger(right).

Secondmessenger

Vacuole

5. Phosphorylatedproteins or secondmessenger initiateresponse.

Ph

osp

ho

ryla

tio

n c

asca

de

Nuclear envelope OR OR

DNA

6. Activate or represstranscription.

6. Activate or represstranslation.

Nucleus

6. Change ion flowthrough channel orpump.

Tropism Recall from Biology that a tropism in plants

is growth in response to a stimulus Phototropism-growth toward light (auxins) Gravitromism-growth in response to gravity

(amyloplasts and auxin) Thigmotropism-growth in response to touch

Thigmomorphogenesis-stunted growth in plants that are mechanically stimulated (due to ethylene production)

Figure 39-8 The phototropic signal is a chemical.

Permeable agar:Shoot bendstoward light

Light Impermeable mica:No bending

Chemical diffusesthrough agar

The hormone can cause bending in darkness.

Allow time forhormone to diffuseinto agar block.

Offset blockscause bendingof shoots not

exposedto light

The hormone causes bending by elongating cells.

Cells on theshaded sideelongate in response tothe hormone(red dots)

Figure 39-16

Roots grow down. Shoots grow up (or out,in some species).

Figure 39-17

Root tips have a protective cap.

Gravity-sensing cells are in the center of the cap.

Cap

Figure 39-18

Gra

vity

Cell in root tip(or shoot)

Amyloplasts arepulled to bottomof cells by gravity

Activated pressure receptors

Figure 39-19

Auxindistribution

AUXIN AS THE GRAVITROPIC SIGNAL

Gra

vit

y

Auxin

1. Normal distributionof auxin in vertical rootprior to disturbance.

2. Root tip moved intohorizontal position.

3. Gravity-sensing cellsactively redistribute theauxin–more goes tobottom side.

4. Asymmetric auxindistribution inhibits cellgrowth on lower sideand stimulates growthon upper side, leadingto bending.

Figure 39-21

Tendril

Figure 39-27

Normal plant

Dwarfedplant

Plant movements

Rapid leaf movements-sensitive plant withers when touched, b/c of an electric impulse (like that of a muscle contraction), causing rapid loss of turgor pressure

Sleep movements-plants lower their leaves at night in response to different turgor pressure in cells

Photoperiodism This is a plant’s response to a seasonal photoperiod

(number of hours of light) Ex: Flowering

Short-day plants-need a long night (less time in the light) and flower in fall or winter

Long-day plants-need a short night (more time in the light) and flower in spring and summer

Day neutral plants-unaffected by photoperiod Critical Night Length-flashing light during the dark

period can throw off a plant’s ability to flower What controls flowering internally?

Buds produce flowers, but photoperiod is detected by the leaves (plants with leaves removed can’t flower)

A bud’s meristem must transition from vegetative growth to flowering

Figure 39-13

How do plants respond to differences in day length?

How do plants respond to nights interrupted by light?

Phytochrome This is the pigment that actually detects the amount

of light striking the plant Has 2 forms: Red and Far Red which are isomers of

one another. Plants synthesize Pr, but sunlight converts it to Pfr At night, the Pfr reverts back to Pr, so the ratio of Pr

to Pfr “tells” the plant how much sunlight it has absorbed

The only thing is, the conversion of fr to r takes place in a few hours, so it doesn’t tell the plant how much darkness it has had. There is another internal circadian rhythm that measures the amount of dark based on when the sun sets and when it rises (informed by phytochrome)

Figure 39-15

Phytochrome(Pr conformation)

Phytochrome(Pfr conformation)

Red light(sunlight)

cis Isomer

Red light:cis to transshape change

Far-red light(shade light)

Photoreversible

trans Isomer

Far-red light:trans to cisshape change

Figure 39-14

Hours Light flash

Long-day(short-night)

plant

Short-day(long-night)

plant

Critical night length

Figure 39-12

Ungerminated lettuce seed

Inhibitsgermination

Red light(sunlight)660 nm

Phytochrome

(Pr conformation)

Germinated lettuce seed

Stimulatesgermination

Phytochrome

(Pfr conformation)

Far-red light(shade light)735 nm

Shape change

Shape change

Plant Responses to Environmental Stress Water Stress-Stomates close b/c of a buildup of ABA Oxygen Deprivation-Plants form air tubes in the root if their

soil is too wet Salt Stress-plants can produce compatible solutes in their

cells to keep from losing water Heat Stress-transpiration does evaporative cooling, plus

they can produce heat-shock proteins that can scaffold the other proteins in the cell to keep them from denaturing

Cold Stress-plants can alter the lipid composition of their plasma membranes, and alter their solute composition to keep the cytosol from freezing

Herbivores-physical and chemical defenses Physical-thorns Chemical-toxins or bad-tasing chemicals Recruitment-plants release chemicals that attract predators of

herbivores (wasps vs. caterpillars)

Figure 39-31STOMATA OPEN IN RESPONSE TO BLUE LIGHT.

Blue light strikes photoreceptor.

1. Pumping by H+-ATPasesincreases. Protons leaveguard cells.

2. K+ and Cl enter cellsalong electrochemicalgradients via inward-

directed K+ channels and

H+/Cl cotransporter.

3. H2O follows by osmosis.

4. Cells swell. Pore opens.

STOMATA CLOSE IN RESPONSE TO ABA.

ABA binds to receptors on guard cells.

1. Pumping by H+-ATPasesstops. Outward-directedCl channels open. Cl

exits along electrochemicalgradient.

2. Change in membranepotential open outward-

directed K+ channels. K+

exits along electrochemicalgradient.

3. H2O follows by osmosis.

4. Cells shrink. Pore closes.

Figure 39-39

Herbivore

Wasp larvae emergingfrom devouredcaterpillar

Plant Defenses against pathogens First line of defense is the epidermis and cutin, however openings, like the

stomata invite infections In general, pathogens gain enough from plants to benefit, but try not to

severely damage or kill the plant Gene-for-gene recognition gives plants specific resistance to disease

Pland has r (resistance) genes, and the pathogen has avr(avirulance) genes. If any one of the plant’s r genes is dominant and corresponds to a dominant avr in

the pathogen, the plant is resistant. If the plant is not resistant to the pathogen, it produces phytoalexins (antimicrobial

agents) and PR proteins (pathogenesis-related) that can attack the infectious agent Hypersensitive Response(HR)-is produced when the plant is resistant to the

pathogen. The plant produces more phytoalexins and PRs, and the plant can “seal” against the pathogen. When the plants seal an infected area, they destroy themselves and a lesion forms

Systematic acquired resistance (SAR)-occurs when the plant releases alarm hormones from the site of the HR response, alerting the rest of the plant of the infection. The other cells then release phytialexins and PRs

Figure 39-34 GENE-FOR-GENE HYPOTHESIS

Virus Bacterium Fungus

1. Pathogens (virus,bacterium, or fungus)enter plant cell viawound or connectionwith infected cell.

2. Pathogens releaseavr gene productsand other molecules.

3. R gene productsfrom host bind toavr gene products.

4. Binding activatesR gene products andtriggers protectivehypersensitiveresponse (HR).

When R and avr geneproducts do notmatch, no HR occursand plant succumbsto disease.

Figure 39-35

Gene-for-gene interactions in a heterozygous plant Gene-for-gene interactions in a homozygous plant

R gene 1 R gene 2 R gene 3 R gene 4 . . . R gene 1 R gene 2 R gene 3 R gene 4 . . .

Figure 39-36

HYPERSENSITIVE RESPONSE (HR)

Ravr

Pathogen

1. An R gene product binds to an avrprotein from a pathogen, triggering thehypersensitive response (HR).

2. The HR includes the production of nitricoxide (NO), reactive oxygen intermediates(ROIs), superoxide ions (O2

–), and phytoalexins.

3. The HR results in the reinforcement ofcell walls, the suicide of infected cells, andthe extermination of invading pathogens.

Deadpathogens

Dead host(no more food for

pathogens)Rein

forced

cell walls surrounding infe

ctio

n site

avrR

Figure 39-39-Table 39-3-1

Figure 39-39-Table 39-3-2

Animal Behavior Nature or Nurture?

Most scientists think it’s about 60% genetic, 40% environment General types

Taxis-Response to a stimulus Reflex-controlled by a reflex arc and is not under brain control Instincts-also called innate behaviors that are thought to be

genetically programmed (although may not be solely due to genes). The broader definition states that these are developmentally fixed behaviors that don’t vary between individuals of a species

Cause of behavior Proximate causes-things that are happening NOW (ex: stimuli,

mechanics of the action, etc)-these tend to be how questions Ultimate causes-the evolutionary reasons for behavior (ex: this

behavior first appeared in an ancestral species)-these tend to be why questions

Figure 51-2

Yawning

Smiling

Languageacquisition

Highly flexibleCondition dependent

Highly stereotypedFixed: little variation

Innate: no modificationthrough learning

Originatesand is modifiedthrough learning

Ethology-The classical study of animal behavior Understanding behavior means understanding the

answers to the following: What stimulus elicits the behavior, and what

physiologic mechanism controls the response? How does the animal’s experience during growth and

development influence the response? How does the behavior aid survival and reproduction? What is the behavior’s evolutionary history?

Fixed Action Pattern (FAP)-sequence of behaviors that once triggered is done to completion. The trigger is called a sign stimulus (ex: moths drop when certain ultrasonic signals occur)

FAPs tend to be simple reactions to limited stimuli Ex: stickleback fish attacking any red-bottomed object

Figure 51-14

Search Approach Terminal

Pulses of high-pitched shouts from bat

When the bat ishere (position 1)…

…the insect ishere (position 1)

Powerdive

12

1 3

2

3

4

Behavioral Ecology This is based on the premise that animals

behave to maximize their evolutionary fitness and is the modern form of ethology. Cost/Benefit (TANSTAAFL)

Foraging Behavior-most foragers are generalists but don’t randomly choose food. In stead, they form a search image of specific characteristics they’re looking for.

When a particular food is scarce, animals can switch search images

There are trade-offs in order to ensure optimal foraging, however Distance of food vs. size of food Energy obtained by food vs. energy used to obtain

the food

Figure 51-3White-fronted bee-eaters are native to East Africa.

Foraging behavior depends on distance traveled.

Birds fly from their nestingcolony to a foraging area,which might be close tothe colony or far away

Other examples of cost/benefit Parental investment-amount of energy invested in

existing offspring at the expense of having additional offspring

Mate choice-involves competition between males, female choice and possibly putting up with different mating schemes Monogamy Polygamy Promiscuity/cheating

Game Theory applications-behaviors can often be explained using game theory Paper, rock, scissors and throat color of the side-

blotched lizard. Orange=aggressive and defend large territories, Blue=small territories, yellow=sneaky

Figure 51-19

Territorialmale

Female

Female-mimicmale

Other behviors studied Migration-how do animals navigate? Rhythmic Behaviors-

Circadian Rhythms-24 hour sleep/wake cycles circannual Rhythms-hibernation and estivation

cycles Signals and Communication-usually a

combination of gestures, postures, calls, touches, and sometimes pheromones (chemicals that animals emit which stimulate a response) Ex: honeybee dances-tell the hive where to find

nectar

Figure 51-16

The round dance The waggle dance

Other bee workers followthe progress of the danceby touching thedisplaying individual

Figure 51-17

Straight runs down the wall of the hive indicate that food isopposite the direction of the Sun.

Straight runs to the right indicate that food is 90 to theright of the Sun.

Downwardwaggle danceon honeycomb

Down

Beehive

Sun

100+ mDown

Food sourceaway from Sun

Sidewayswaggle danceon honeycomb

100+ m

Beehive

90

Sun

Food sourceat right angleto Sun

Learning This is an experienced-based behavior modification Learning can affect developmentally fixed behavior, but not

vice-versa There’s often a distinction between maturation and learning (birds can “learn” to fly, even if in isolation)

Types of learning Habituation-getting used to a repeated stimulus Imprinting-time sensitive learning during a critical period

that is irreversable (organism learns who their parents are and therefore mimics them)-Konrad Lorenz

Spatial Learning-Tinbergen’s wasp study Insight-performing a behavior correctly without any prior

experience, this is different from observational learning Operant conditioning-trial and error learning (rats in

mazes)-B.F. Skinner Classical Conditioning-associative learning (Pavlov’s dogs)

Figure 51-7

Learning Leads to. . . Warning coloration-a predator only has to

know 1 warning color pattern in order to avoid danger Mimicry-animals looking dangerous by

mimicking others’ warning coloration. Sometimes they’re also dangerous, sometimes they’re not.

Play-practice aggression and social behavior

Cognition?-Some animals have problem-solving abilities that lead to things like tool use

Figure 51-18c

This butterfly looks like a bad-tasting species but actually tastes good

What about the genetics of behavior?

Cross-fostering studies are helpful in understanding the extent to which behavior can be modified by environment

Scientists have also looked at organisms reared in isolation that exhibit behaviors perfectly, indicating genetic regulation of behavior

Inclusive fitness and Social Behaviors Why would an organism do an altruistic (not

for it’s own fitness) act? Ex: prarie dogs and alarm calls, bees not

mating, etc Kin selection-ensuring that your close

relatives reproduce ensures your genome’s survival (inclusive fitness)

Hamilton’s rule=rB>C r=coefficient of relatedness B=benefit C=Cost

Figure 51-21 What is the r between half-siblings?

Probability that mothertransmits a particularallele to son is 1/2

Probability that mothertransmits a particularallele to daughter is 1/2

What is the probability that half-siblings inherit the same allele from theircommon parent?Answer: r between half-siblings = 1/2 1/2 = 1/4

What is the r between full siblings?

Probability that fathertransmits a particularallele to daughter is 1/2(same for both arrows)

Probability that mothertransmits a particularallele to daughter is 1/2(same for both arrows)

What is the probability that full siblings inherit the same allele from their fatheror their mother?Answer: Probability that they inherit same allele from father = 1/2 1/2 = 1/4

Probability that they inherit same allele from mother = 1/2 1/2 = 1/4Overall probability that they inherit the same allele = 1/4 + 1/4 = 1/2r between full siblings = 1/2

Social Structures

Eusociality-organisms like termites, ants, and bees that are haplodiploid Females arise from fertilized eggs Males arise from unfertilized eggs

Hierarchies-based on dominance Territorial behavior-reinforced by

agonistic (aggressive) behaviors Reciprocal altruism