Biology 3.3“Plant & Animal Responses”

Tropisms

Plants grown on the ISS

• Grown in light + zero gravity

• Grown in darkness + zero gravity

Plant Hormones (for chemists)

Auxin Cytokinins (zeatin) Gibberellins (GA3)

Abscisic Acid Ethylene

Nasties

Kineses

Slater – Porcellio scaber

Slater – Porcellio scaberHygrokinesis

Original: 1 frame/5 sec

The top half of the container is a high humidity environment. The Bottom is a low humidity environment.Note that animals stay in the high humidity environment.

(Original: 1 frame/60 seconds)

http://cas.bellarmine.edu/tietjen/Ec&Ev_Distance_learning/EcologyIntro/behavior.htm

Taxes

Slater Phototaxis• Task: Design and carry

out an experiment using choice chambers to demonstrate whether or not slaters show phototaxis.

• Consider: how MUCH of a difference in responses will be sufficient to be able able state that there is a REAL difference!

http://www.cvsd.org/university/classpage/jgriffith/pages/AP%20Items/13%20Animal%20control/11%20-%20Animal%20Behavior.htm

Slater Phototaxis (13 Bio 2012)• Aim: Do slaters prefer light or dark habitats?• Hypothesis: That slaters prefer dark habitats (because this

will help them avoid desiccation)• Results:

• Conclusions:

Slater Phototaxis (13 Bio 2011)• Aim: Do slaters prefer light or dark habitats?• Hypothesis: That slaters prefer dark habitats (because this will

help them avoid desiccation)• Results:

• Conclusions: Hypothesis proved correct, slaters prefer darker habitats. Slaters were nearly 5 times more likely to be found in the dark. We suspect, therefore, there is a strong preference to avoid drying out and being visible to predators.

Number of Slaters

Dark Light

Average 9.0 1.9

"Do Slaters Show Phototaxis?"

Migration

NZ Shining Cuckoo: Breeds NZ + Chathams, migrates to Solomon Islands

Migration

Migration: the mass movement of a large number of animals of the same species often over a large distance.

Migration is an important response to seasonal environmental change. In true migration animals usually travel from one location where they breed to another where they feed and then they move back again.

Migration Features– Active (eg swimming), not passive dispersal (drifting in current)– Usually to feeding / breeding area– Usually two-way trip– Usually regular timing– Often long distance– Often at defined life stage– Initiated by internal clocks / timekeepers in resonse to

environmental cues (eg temp. change, daylength change)– -’s risky and costly in terms of energy – death is the ultimate

energy cost– +’s safe breeding grounds, avoid climate extremes, maintain

food supply (seasonal, food supply used up)– Eg: salmon – adults migrate up rivers to spawn– Eg: humpback whale feed at pole in summer, breed in tropics– Moving on because of food source depletion (locust) might not

count as migration.

Homing

HomingHoming The ability of an animal to return to home over unfamiliar territory.

Key FeaturesDistances can be relatively short (may use familiar landmarks)Usually on a regular (eg daily, tidal) basis

Involves navigation

ExamplesHoming pigeons returning to loftChitons to home indentation on a rock Limpet ‘home scar’

Navigation

Bee Navigation• Waggle Dance: uses solar navigation

– In vertical hive combs:• Angle of dance to vertical indicates horizontal angle

from sun to food• Speed, duration of waggle indicates closeness of food

(Must have a biological clock to account for the fact that the sun moves across the sky and the angle to the food will have changed by the time they get back to the hive).

• Round Dance: indicates food closer than 50m– “go and look nearby and you’ll find food”

Monarch Navigation• Flight patterns appear to be inherited, based on a

combination of the position of the sun in the sky and:

• Time-compensated sun compass – based in their antennae.

• New research shows: use the earth's magnetic field – Antennae protein is sensitive to violet/blue, in that light

it can function as a chemical compass indicating alignment to magnetic field (or not). Can’t tell N/S

Female Male

Timing Responses

Petrolisthes elongatus, half crab

Astronomical Cycles

Solar year – 365.25 days (rotations) of Earth in one orbit (revolution) around the sun.

Lunar month – 29.5 days between full moons

Earth day – 23 h 56min 4.09s (to rotate on axis once)

Seasons – Caused by tilt of Earth’s axis in conjunction with orbit around sun (23.5°)

Tidal XXXXX

Actograms

• Actogram — chart commonly used to plot activity against time

Night

Activity

No Activity

Day

24 hours

For the first 7-days mice were maintained under a 12-hour light: 12-hour dark cycle, and subsequently mice were maintained in constant darkness.

When the animal is placed into constant darkness, the period of the free-run driven by the endogenous clock at around 23.5 hour cycles, is apparent with activity starting earlier each day.

What is happening here?

An illustration of the effect of SCN lesions on a sample slave rhythm.  Under a 12:12 dark:light cycle, an intact nocturnal animal, such as a rat, is active during the dark phase of the DL cycle.  Almost immediately following ablation of the SCN (SCNX), the animal's rhythms become completely arrhythmic in the circadian time domain

My Body Temp Rhythm

Aim: to find out whether we can demonstrate our own daily temperature variation.

Method: Hourly thermometer readings, at rest (as much continuous data as possible)

Conclusions:

• SDP flower with short day and long night. But if you interrupt a long night with light then SDP don’t flower. This shows that the long nights make them flower as short nights (leaving the short day intact) stops them flowering.

• LDP flower with long day and short night. But if you interrupt a long day with darkness then LDP still flower. This shows that the short nights make them flower as short days (leaving the short night intact) keepsw them flowering.

Social Organisation

Communication

Communication

• Essential for organisms to interact appropriately with others of the species

• Encompasses many types of signals – Visual: vervet monkey (shows blue testicles to indicate gender) – Touch: slaters (communicates presence, enable clumping

behaviour)– Sound: blackbird (squawk when cat present)– Smell: skunk (warns predators)

• The more complex the social organisation the more complex the signals.– Simple: Sheep – higher pitched baa “I’ve lost my baby”…not

much other signals.– Complex: Chimps – grooming behaviour (maintaining social

bonds)

Sexual Dimorphism

Nyala

Pheasant

Terrapin

m.

f.

Co-Operative Behaviour

• Bees vs Hornets

(see text resource: http://scienceblogs.com/neurophilosophy/2007/09/19/mobs-of-honeybees-kill-hornets-by/

http://blogs.discovermagazine.com/notrocketscience/2009/07/05/mobs-of-honeybees-suffocate-hornets-to-death/)

http://www.youtube.com/watch?v=JDSf3Kshq1M

http://www.youtube.com/watch?v=Zjp31TwooSM

http://www.youtube.com/watch?v=bzvbSzfke7c