Transcript Behavioral Cycles Amongst Different Organisms

Behavioral Cycles Among
Different Organisms
Behavioral Cycles in Plants
• Plant Dormancy
– Is a temporary state of
reduced rate or no
internal activity (Scott
Freeman, 2003,
pg.898) .
– Different chemicals
(hormones) in the
plant activate the plant
to start growing and
for it to go into
dormancy.
Tree Dormancy
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Both chlorophyll and carotenoids
are present in the chloroplasts of
leaf cells throughout the growing
season.
During the growing season,
chlorophyll is continually being
produced and broken down and
leaves appear green.
As night length increases in the
autumn, chlorophyll production
slows down and then stops and
eventually all the chlorophyll is
destroyed.
The carotenoids and anthocyanins
that are present in the leaf are
then unmasked and show their
colors.
This is what causes leaves to
change color and for trees to lose
their leaves for the winter
(dormant).
http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm
Seed Dormancy
• Seed dormancy is the state
seeds are in before they start
growing.
• Seeds experience dormancy
so they don’t start growing in
conditions that won’t allow
them to survive (drought, or
winter).
• Dormancy is broken when
optimal growing conditions are
present.
• Water, sunlight, temperature
are some ways to break
dormancy (Scott Freeman,
2003, pg.926) .
Behavioral Cycles in Animals
• Hibernation occurs when
temperatures lower and winter
conditions cause food to become
scarce.
• Animals (squirrels, voles, mice)
must seek a well insulated shelter
and reduce their internal activity
(metabolic activity) which will lower
their internal temperature (Scott
Freeman, 2003, pg.948).
• During hibernation (torpor) animals
reduce their internal temperature,
heart rate, oxygen intake.
• This saves animals precious energy
they need due to lack of resources.
How Organisms Migrate?
• Migration is long-distance
movement of a population
associated with a change of
seasons. (Scott Freeman,
2003, pg.1148).
– Examples:
• Arctic terns nest along the
Atlantic coast of North
America, fly south along the
coast of Africa to Antarctica
(total of 20,000 miles).
• Monarch butterflies travel
from all over the North to
Central Mexico or southwest
California.
• Salmon when they hatch
migrate to the ocean where
after feeding and growing for
several years return to where
they spawn and then die.
How do Animals Migrate?
• Piloting- Use familiar
Landmarks where offspring
follow their parents and
memorize the routes.
• Compass Orientation- Oriented
in a specific direction based on
the Sun during the day and the
Stars at night.
• True Navigation- Birds can
detect magnetism by their
visual system and have small
particles of magnetic iron.
– Changes in the positions of
magnetic particles, in
response to Earth’s
magnetic field.
(Scott Freeman, 2003, pg.1149).
References
• Scott Freeman, S. (2003). Biological
science. (2 ed., pp. 494-512). Upper
Saddle River, New Jersey: Pearson
Prentice Hall.
• http://www.na.fs.fed.us/fhp/pubs/leaves/lea
ves.shtm