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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