Unit 6Ecology Study Guide
Unit 6Ecology Study Guide
-Behavioral ecology: study of interaction between animals and their environments.
-Ethology: study of animal behavior
-Imprinting: innate behavior learned during critical period early in life (baby ducks imprint to mama ducks)
-Migration: cyclic movement of animals over long distances according to the time of year.
-Taxis: reflex movement toward or away from a stimulus
-Coefficient of relatedness: statistic that represents the average proportion of genes two individuals have in common. The higher the value, the more likely they are to help one another.
-Chemical: communication through the use of chemical signals, such as pheromones
-Visual: communication through the use of visual cues, such as the tail feather displays of peacocks
-Auditory: communication through the use of sound, such as the chirping of frogs in the summer
-Population: collection of individuals of the same species living in the same geographic area
-Community: collection of populations of species in a geographic area
-Ecosystem: community + environment
-Biosphere: communities + ecosystems of the planet
-Biotic components: living organisms of ecosystem
-Abiotic components: nonliving players in ecosystem
-Dispersion patterns:
- Clumped dispersion: animals live in packs spaced from each other (e.g. cattle)
- Uniform distribution: species are evenly spaced out across an area (e.g. birds on a wire)
- Random distribution: species are randomly distributed across an area,( e.g. trees in a forest)
-Biotic potential: maximum growth rate for a population
-Carrying capacity: maximum number of individuals that a population can sustain in a given environment
-Limiting factors: factors that keep population size in check
- Density dependent (food, waste, disease)
- Density independent (weather, natural disasters)
-Population growth
- Exponential growth (J shaped curve, unlimited growth)
- Logistic growth (S shaped curve, limited growth)
-Life history strategies:
- K-selected populations (constant population size or growth, low reproductive rate, extensive parental care – kangaroos)
- R-selected population (rapid population growth, J curve style, little parental care, quick reproduction, high death rate – roaches)
-Survivorship curves: show survival rates for different-aged members of a population
- Type I: live long life, until age is reached where death rate increases rapidly – humans, large mammals
- Type II: constant death rate across the age spectrum – lizards, small mammals
- Type III: steep downward death rate for young individuals that flattens out at certain age – fish, oysters, sea turtles
-Parasitism: one organism benefits at another’s expense (ticks and humans)
-Commensalism: one organism benefits while the other is unaffected (clownfish and anemones)
-Mutualism: both organisms benefit from the interaction (acacia trees and ants)
-Competition: both species are harmed by the interaction
-Predation: one species, the predator, hunts the other, the prey
-Primary succession: occurs in area devoid of life that contains no soil
- Pioneer species come in, add nutrients, and are replaced by future species which attract animals to the area, thus adding more nutrients
- Constant changing until the climax community is reached and a steady-state equilibrium is achieved
-Secondary succession: occurs in area that once had stable life but was disturbed by major force (fire)
-Trophic levels: hierarchy of energy levels on a planet; energy level decreases from bottom to top; primary producers (bottom) primary consumers (herbivores) secondary consumers tertiary consumers decomposers