Transcript Behavior Notes

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
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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 piece
of plant tissue.
2. Callus grows.
3. Roots form.
4. Shoots form.
Figure 39-33
LEAF SENESCENCE AND ABSCISSION
Senescent leaf
Healthy leaf
Age, drought, temperature,
day length, etc. reduce
auxin production from leaf
Abscised leaf
A protective layer has
formed to seal stem
where leaf was attached
Abscission zone
1. High auxin: Cells in abscission
2. Low auxin: Cells in abscission
3. Leaf detaches at the
zone are insensitive to ethylene.
Leaf functions normally.
zone become more sensitive to
ethylene, leading to leaf senescence.
abscission zone.
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
Lateral
shoots
Figure 39-24
Gradient of auxin concentration
Apical end (toward shoot)
2H+
Auxin
Auxin
Cotransporters
at top of cells
bring auxin in
Some auxin
molecules are
destroyed by
enzymes as
they travel down
Carrier proteins
at bottom of cells
send auxin out
Basal end (toward root)
How do hormones work?
 Usually, there’s a signal transduction
pathway involved
Figure 39-1
STEPS IN INFORMATION PROCESSING
External stimulus
on receptor cell
Internal
signal
1. Receptor cell
perceives external
stimulus and
transduces the
information to an
internal signal.
2. A hormone
Cell-cell
signal
(cell-cell signal)
released by the
receptor cell travels
throughout the body.
3. Receptor cells
Internal
signal
receive the hormonal
(cell-cell) signal,
transduce it to an
internal signal, and
change activity.
SIGNAL TRANSDUCTION
1. Signal
Cell wall
2. Receptor protein changes
in response to signal.
Cell membrane
ATP
ADP
ATP
ADP
Phosphorylation cascade
Figure 39-2
3. Receptor or associated protein
catalyzes phosphorylation reaction.
4. Phosphorylated
protein triggers
phosphorylation
cascade (left)…
ATP
…OR release of
second messenger
(right).
ADP
Vacuole
ATP
Second
messenger
ADP
5. Phosphorylated
proteins or second
messenger initiate
response.
OR
OR
DNA
6. Activate or repress
transcription.
6. Activate or repress
translation.
Nucleus
6. Change ion flow
through channel or
pump.
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.
Light
Permeable agar:
Impermeable mica:
Shoot bends
toward light
No bending
Chemical diffuses
through agar
The hormone can cause bending in darkness.
Allow time for
hormone to diffuse
into agar block.
Offset blocks
cause bending
of shoots not
exposed
to light
The hormone causes bending by elongating cells.
Cells on the
shaded side
elongate in
response to
the 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.
Cap
Gravity-sensing cells are
in the center of the cap.
Figure 39-18
Gravity
Cell in root tip
(or shoot)
Amyloplasts are
pulled to bottom
of cells by gravity
Activated pressure receptors
AUXIN AS THE GRAVITROPIC SIGNAL
Auxin
distribution
Auxin
Gravity
Figure 39-19
1. Normal distribution
of auxin in vertical root
prior to disturbance.
2. Root tip moved into
horizontal position.
3. Gravity-sensing cells
actively redistribute the
auxin–more goes to
bottom side.
4. Asymmetric auxin
distribution inhibits cell
growth on lower side
and stimulates growth
on upper side, leading
to bending.
Figure 39-21
Tendril
Figure 39-27
Normal plant
Dwarfed
plant
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)
Red light
(sunlight)
Phytochrome
(Pfr conformation)
Red light:
cis to trans
shape change
Far-red light
(shade light)
Photoreversible
cis Isomer
Far-red light:
trans to cis
shape change
trans Isomer
Figure 39-14
Hours
Light flash
Critical night length
Long-day
(short-night)
plant
Short-day
(long-night)
plant
Figure 39-12
Ungerminated lettuce seed
Red light
(sunlight)
660 nm
Inhibits
germination
Phytochrome
(Pr conformation)
Germinated lettuce seed
Far-red light
(shade light)
735 nm
Shape change
Shape change
Stimulates
germination
Phytochrome
(Pfr conformation)
Plant Responses to Environmental
Stress
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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
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Physical-thorns
Chemical-toxins or bad-tasing chemicals
Recruitment-plants release chemicals that attract predators of
herbivores (wasps vs. caterpillars)
Figure 39-31
STOMATA OPEN IN RESPONSE TO BLUE LIGHT.
Blue light strikes photoreceptor.
STOMATA CLOSE IN RESPONSE TO ABA.
ABA binds to receptors on guard cells.
1. Pumping by H+-ATPases
1. Pumping by H+-ATPases
increases. Protons leave
guard cells.
stops. Outward-directed
Cl channels open. Cl
exits along electrochemical
gradient.
2. K+ and Cl enter cells
2. Change in membrane
along electrochemical
gradients via inwarddirected K+ channels and
H+/Cl cotransporter.
potential open outward-
3. H2O follows by osmosis.
3. H2O follows by osmosis.
4. Cells swell. Pore opens.
4. Cells shrink. Pore closes.
directed K+ channels. K+
exits along electrochemical
gradient.
Figure 39-39
Herbivore
Wasp larvae emerging
from devoured
caterpillar
Plant Defenses against pathogens
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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
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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.
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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
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 via
wound or connection
with infected cell.
2. Pathogens release
avr gene products
and other molecules.
3. R gene products
from host bind to
avr gene products.
4. Binding activates
R gene products and
triggers protective
hypersensitive
response (HR).
When R and avr gene
products do not
match, no HR occurs
and plant succumbs
to disease.
Figure 39-35
Gene-for-gene interactions in a heterozygous plant
R gene 1
R gene 2
R gene 3
R gene 4 . . .
Gene-for-gene interactions in a homozygous plant
R gene 1
R gene 2
R gene 3
R gene 4 . . .
Figure 39-36
HYPERSENSITIVE RESPONSE (HR)
Dead
pathogens
Pathogen
R
avr
R
avr
Dead host
(no more food for
pathogens)
1. An R gene product binds to an avr
2. The HR includes the production of nitric
3. The HR results in the reinforcement of
protein from a pathogen, triggering the
hypersensitive response (HR).
oxide (NO), reactive oxygen intermediates
(ROIs), superoxide ions (O2–), and phytoalexins.
cell walls, the suicide of infected cells, and
the extermination of invading pathogens.
Figure 39-39-Table 39-3-1
Figure 39-39-Table 39-3-2
Animal Behavior
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Nature or Nurture?
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Most scientists think it’s about 60% genetic, 40% environment
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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
General types
Cause of behavior
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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
Innate: no modification
through learning
Smiling
Highly stereotyped
Fixed: little variation
Highly flexible
Condition dependent
Language
acquisition
Originates
and is modified
through 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
1
2
1
3
2
When the bat is
here (position 1)…
Search
…the insect is
here (position 1)
Approach
3
Power
dive
Terminal
4
Pulses of high-pitched shouts from bat
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 51-3
White-fronted bee-eaters are native to East Africa.
Birds fly from their nesting
colony to a foraging area,
which might be close to
the colony or far away
Foraging behavior depends on distance traveled.
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 sideblotched lizard. Orange=aggressive and defend large
territories, Blue=small territories, yellow=sneaky
Figure 51-19
Territorial
male
Female
Female-mimic
male
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 follow
the progress of the dance
by touching the
displaying individual
Figure 51-17
Straight runs down the wall of the hive indicate that food is
opposite the direction of the Sun.
Downward
waggle dance
on honeycomb
Sun
Straight runs to the right indicate that food is 90 to the
right of the Sun.
Sun
Sideways
waggle dance
on honeycomb
Beehive
Beehive
90
Down
Down
100+ m
Food source
away from Sun
100+ m
Food source
at right angle
to Sun
Learning
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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 problemsolving 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 mother
transmits a particular
allele to son is 1/2
Probability that mother
transmits a particular
allele to daughter is 1/2
What is the probability that half-siblings inherit the same allele from their
common parent?
Answer: r between half-siblings = 1/2  1/2 = 1/4
What is the r between full siblings?
Probability that father
transmits a particular
allele to daughter is 1/2
(same for both arrows)
Probability that mother
transmits a particular
allele to daughter is 1/2
(same for both arrows)
What is the probability that full siblings inherit the same allele from their father
or 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 = 1/4
Overall probability that they inherit the same allele = 1/4 + 1/4 = 1/2
r 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