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K-strategist populations are more commonly regulated by ____________ limiting factors, and r-strategist populations are regulated by ___________ limiting factors.
K-strategist populations are more commonly regulated by density-dependent limiting factors. Their population sizes hover around a carrying capacity that is dependent on factors that increase in severity with the density of the population. On the other hand, r-strategist populations are regulated by density-independent limiting factors. They reproduce rapidly until a density-independent factor causes many of them to die.
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A species designated as "r-strategist" is characterized by all of the following except __________.
Species described as "r-strategist" have a survival strategy of producing large numbers of offspring, a short life expectancy, and typically smaller body sizes. Examples include mice, locusts, and frogs. These species survive by producing lots of offspring, since many individuals don't survive to adulthood.
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K-strategist species exhibit all of the following characteristics except __________.
Species designated as K-strategists thrive through longevity and have a higher survival rate at birth, but produce far fewer offspring. Examples include elephants and whales. Consider an elephant; it may produce relatively few baby elephants, but these baby elephants each have the potential to live relatively long lives. On the other hand, contrast K-strategists like elephants with r-strategists like rats, locusts, and flies. These species are designated as r-strategists because in contrast, they produce numerous offspring, few of which may survive to adulthood, and each one of which reaches maturity quickly and lives a relatively short life. K-strategists in general spend more time than r-strategists caring for and raising their offspring; they have fewer offspring, so they put more care into ensuring the survival of each one. Contrast elephants with frogs to see this difference; elephants care for their young, while frogs lay their eggs and care for their offspring very little, if at all.
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What does a J curve represent on a population growth chart?
Population growth can follow either a J curve trend or an S curve trend. A J curve represents exponential, or unrestricted growth. An S curve represents logistic, or restricted, growth and accounts for the carrying capacity of an environment.
In a J curve model, the population will continue to grow even when it has reached capacity. In an S curve model, the population will stagnate and stabilize at a maximum value when capacity is reached.
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Which of the following most accurately describes a deme?
A deme is defined as a group of individuals more genetically similar to each other than to other individuals, even if spatially isolated. A group of conspecific individuals separated demographically, genetically, or spatially from other groups is a population**.** A set of spatially disjunct populations in which some immigration still occurs is a metapopulation**.** The other options are not well-defined in population ecology.
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There are several different kinds of survivorship curves for different kinds of animals. What kind of survivorship curve do organisms with little to no parental care generally exhibit?
Organisms with little to no parental care typically have large amounts of offspring to compensate for high mortality rates of the young, as shown in a type III survivorship curve. These include organisms like trees, which spread large numbers of seeds because the seeds rarely find a good growing spot and mature to adulthood.
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