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 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).

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 ). Upper Saddle River, New Jersey: Pearson Prentice Hall. aves.shtmhttp:// aves.shtm