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Entry Task: What is the difference between a biotic factor and an abiotic factor? Learning Target: Understand the differences between abiotic/biotic and the concept of a niche. Language Objective: Describe an ecosystem’s biotic and abiotic factors.
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Entry Task: • What is the difference between a biotic factor and an abiotic factor? • Learning Target: • Understand the differences between abiotic/biotic and the concept of a niche. • Language Objective: • Describe an ecosystem’s biotic and abiotic factors. • Describe organism in terms of its habitat and niche.
Factors • What is a biotic factor? • Any biological influence on an organism. • Includes all other living organisms in the ecological community. • What is an abiotic factor? • Any physical, non-living influence on an organism. • Both determine survival and growth of an organism as well as ecosystem productivity.
Recognizing Factors - QUIZ!! 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
Habitat • What is a habitat? • Where an organism lives. • Includes biotic and abiotic factors. • Ex: for a frog, it could be a pond.
Niche • What is a niche? • Full range of conditions in which an organism lives, both biological and physical, and how an organism uses these conditions. • No two species can share the same niche, but niches can be similar.
What’s your niche? • Make a personal place map. • This will be a brief sketch in your notebook. • What characteristics make it special to you? • Draw 5 biotic factors and label • Draw 5 abiotic factors and label • Does anyone else like this place just the same way as you do? Why is it special only to you?
Entry Task: • What are the six classifications of community interactions? • Learning Target: • Be able to recognize what type of interaction is occurring in an ecological community. • Language Objective: • Describe interactions in an ecological community using the proper terms associated with these interactions.
Competition • What is competition? • Both organisms want the same thing. Niches develop as a way to reduce competition. • Competitive Exclusion Principle: • No two species can occupy the same exact niche in the same habitat at the same time, so they compete for resources and mates.
Predation • What is predation? • Interaction in which one organism captures and feeds on another organism. • What is a predator? • The organism that feeds on another organism. • What is the prey? • The organism that gets fed upon by the predator.
Symbiosis • What is symbiosis? • Any relationship in which two species live closely together. • There are three main types of symbiosis
Symbiosis - Mutualism • What is mutualism? • Both organisms benefit. • Ex: Each June in California's hot San Joaquin Valley, paper bags containing wasp and pollen-bearing caprifigs are stapled to limbs in Calimyrna fig orchards. • Ex: Bacteria in an organism’s gut and on its skin usually have a mutualistic relationship with the organism.
Symbiosis - Commensalism • What is commensalism? • One member of the relationship benefits, but the other is neither helped nor harmed. • Ex: Barnacles can be seen on the back of this gray whale. This association doesn’t hurt the whale, but the barnacles get a free ride.
Symbiosis - Parasitism • What is parasitism? • The relationship harms one of the members. • An organism that lives on or in another organism causes direct harm to this “host” • Ex: Leeches, harmful bacteria, ticks, deer liver flukes
“Community Interactions in the High School” Skits • Groups of five • On the butcher paper at your station, include the following: • Definition of your assigned interaction (in your own words). See p.92 • Example of your interaction in nature. • Create a short skit involving ALL group members of this interaction in a high school setting. • YOU HAVE 15 MINUTES…. GO! 1. Competition 3. Mutualism 2. Predation 4. Commensalism 5. Parasitism
Relationships in your Niche • Describe three examples of community interactions seen during today’s skits that take place in your niche (personal place). • These should be labeled and on the back of your poster for “What’s Your Niche?”
Entry Task: • What is population density? • What are the two types of population growth? • Learning Target: • Be able to recognize which type of population growth is occurring and what might affect population size. • Language Objective: • Describe population changes using terms such as population density, immigration, emigration, growth (exponential and logistic), and carrying capacity.
Populations • What is a population? • A group of individuals in the same area • What characterizes a population? • Geographic distribution, range (where they are) • Density (individuals per unit area) • Growth rate (how the size of a population changes) • Age structure (Chpt. 5-3)
Population Density • There are 200 bull frogs living in a pond that covers 4 square kilometers… What is the density of the bull frog population? • Population density = # individuals / Unit Area • 200 bull frogs / 4 km2 = 50 bull frogs / km2
Human Population Densities • Wenatchee: 451/square mile • New York City: 27, 532/square mile • Mumbai, India: 1,000,000/square mile
Population Growth • What affects population size? • # births • # deaths • # of individuals entering (immigration) or leaving (emigration) • When does growth occur? • Birthrate > deathrate • Immigration > emigration
Types of Population Growth • Exponential growth • J-shaped curve, constant rate of growth • Occurs when there are unlimited resources and no predation or disease. This are known as ideal conditions.
Types of Population Growth • Logistic Growth • Natural populations do not exhibit exponential growth all the time… • Cases when growth slows or stops: • As resources decrease • Deathrate = birthrate • Immigration = emigration • Individuals a given environment can support = Carrying capacity.
Logistic Growth • Always some fluctuation or slight changes that make it so a population is not AT carrying capacity all the time