Understanding Populations
Chapter 8
Population
• All of the members of a species living in the same place at the same time
• All of the brown squirrels living in a forest
• Density - the number of individuals per unit area or volume
• Dispersion - the relative distribution or arrangement of its individuals within a given amount of space
Clumped Dispersion
• Description of a large population of geese gathered in a marsh
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Density Independent
• Cause of death that does not occur more quickly in crowded populations
• Growth Rate - Birth rate minus the death rate
• Birth rate - Death rate = Growth Rate
• Reproductive Potential - the maximum number of offspring that each member of the population can produce
Generation Time
• Average age at which members of a species reproduce
• Exponential growth - when populations grow faster and faster
• Carrying Capacity - the maximum number of a species that an ecosystem can support
Niche
• The unique role of a species within an ecosystem
• Kangaroo’s role as a large herbivore on Australian grasslands
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Competition
• A relationship in which different individuals or populations attempt to use the same limited resource
• Woodpeckers eating at a birdfeeder QuickTime™ and a
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Predation
• When an organism (predator) eats another organism (prey)
• An owl snatching a mouse from a field to eat
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Parasitism
• When an organism, parasite, takes its nourishment from its host
• Three lampreys attached to a fish and sucking its body fluids for foodQuickTime™ and a
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Mutualism
• A close relationship between two species in which each species provides a benefit to the other
• A butterfly pollinating a flower as it drinks nectar from the flowerQuickTime™ and a
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Commensalism
• A relationship in which one species benefits and the other species is neither harmed nor helped
• An orchid using a high tree branch as a place of attachment to receive more sunlight but not affecting the treeQuickTime™ and a
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• Symbiosis - a relationship in which two organisms live in close association
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• The number of wild horses per square kilometer in a prairie is the horse population’s?
• Density
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• If over a long period of time each pair of adults in a population had only two offspring and the offspring lived to reproduce, the population would?
• Remain the same
• Which of the following species has the highest reproductive potential?
• Rabbit, Elephant, Human, Horse?
• Rabbit
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• Which of the following is not an example of exponential growth?
• Rabbit populations after being introduced to Australia
• Reindeer of the Probilof Islands eating most of the Lichens
• A bank account that earns interest• Mold appearing on bread overnight• B
• The carrying capacity of an environment for a particular species at a particular time is determined by the:
• Supply of the most limited resources
• Competition for food cannot occur:
• Between animals from two different ecosystems
• A bird that feeds at night and a bird that feeds during the day from the same flower is an example of:
• Indirect Competition
• In which type of interaction between species does one species benefit by harming another species but not killing it?
• Parasitism
• Which of the following examples would be least likely to be considered a symbiotic interaction?
• A kit fox hunts and feeds on a kangaroo rat
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• Which of the following two species represent a relationship that has coevolved?
• Flowering plants and their pollinators
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