Reproductive Patterns and Principles - AP Environmental Science
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Which of these animals is a K-selected species?
Which of these animals is a K-selected species?
Elephants are large-bodied and give birth to only one offspring every few years, and mothers have a large role as caregivers to ensure the survival of their young. The other species listed here are r-selected species and have many offspring at a time. In some cases, r-selected species do not parent. In others, offspring mature very quickly and parents do not have to provide care for very long.
Elephants are large-bodied and give birth to only one offspring every few years, and mothers have a large role as caregivers to ensure the survival of their young. The other species listed here are r-selected species and have many offspring at a time. In some cases, r-selected species do not parent. In others, offspring mature very quickly and parents do not have to provide care for very long.
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A population of dingoes in an Outback region of Australia includes 120 individuals at the start of 2011. At the start of 2012, researchers had observed 18 births and 2 deaths. In addition, they observed 2 individuals immigrating and 3 individuals emigrating. What is the population's net growth rate?
A population of dingoes in an Outback region of Australia includes 120 individuals at the start of 2011. At the start of 2012, researchers had observed 18 births and 2 deaths. In addition, they observed 2 individuals immigrating and 3 individuals emigrating. What is the population's net growth rate?
The population's new size at the start of 2012 was = original population + (births + immigrations) - (deaths + emigrations) = 120 + (18 + 2) - (2 + 3) = 135. Then, the net population growth rate is equal to (net change in population / size of old population) = 15/120 = .125.
The population's new size at the start of 2012 was = original population + (births + immigrations) - (deaths + emigrations) = 120 + (18 + 2) - (2 + 3) = 135. Then, the net population growth rate is equal to (net change in population / size of old population) = 15/120 = .125.
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A species designated as "r-strategist" is characterized by all of the following except __________.
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.
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 __________.
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.
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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Corals often coordinate spawning so that, in the span of one night, thousands of gametes are released at once. Predatory fish are typically overwhelmed by the amount of potential prey and cannot possibly consume every gamete.
Corals are considered __________.
Corals often coordinate spawning so that, in the span of one night, thousands of gametes are released at once. Predatory fish are typically overwhelmed by the amount of potential prey and cannot possibly consume every gamete.
Corals are considered __________.
Corals are r-selected species, categorized by producing many offspring at once, which individually have low chances of survival, and short lifespans. Other r-strategists include rodents, insects, and other small-bodied, early-maturing animals. K-selected species produce few offspring and invest lots of parental care to ensure a higher chance of survival. Humans are an example of a K-selected species.
Corals are r-selected species, categorized by producing many offspring at once, which individually have low chances of survival, and short lifespans. Other r-strategists include rodents, insects, and other small-bodied, early-maturing animals. K-selected species produce few offspring and invest lots of parental care to ensure a higher chance of survival. Humans are an example of a K-selected species.
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Nigeria is experiencing a fertility rate of roughly seven children per woman and a population structure where roughly forty percent of the population is under the age of fifteen. What would be the most accurate projection of the population in coming years?
Nigeria is experiencing a fertility rate of roughly seven children per woman and a population structure where roughly forty percent of the population is under the age of fifteen. What would be the most accurate projection of the population in coming years?
In terms of population trends, Nigeria can expect to see exponential growth in the following years for two reasons: Fertility rates are already quite high (e.g. a stable population is at 
births per female) and a large portion of the population is under the age of fifteen. Present fertility rates ensure current exponential growth, while a large proportion of the population reaching reproductive age ensures future population growth, especially if the fertility rate remains inflated.
In terms of population trends, Nigeria can expect to see exponential growth in the following years for two reasons: Fertility rates are already quite high (e.g. a stable population is at
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Which of the following mammals is an "r-selected" species?
Which of the following mammals is an "r-selected" species?
R-selected individuals are characterized by the following: early age of sexual maturity, many lifetime reproductive events, large numbers of offspring per event, and minimal parenting. Many of the offspring of r-selected species will die before adulthood. On the other hand, K-selected individuals have only one or few offspring at once and invest larger amounts of time and energy into parenting to ensure survival. The rabbit is the only species listed whose life traits can be categorized as being r-selected.
R-selected individuals are characterized by the following: early age of sexual maturity, many lifetime reproductive events, large numbers of offspring per event, and minimal parenting. Many of the offspring of r-selected species will die before adulthood. On the other hand, K-selected individuals have only one or few offspring at once and invest larger amounts of time and energy into parenting to ensure survival. The rabbit is the only species listed whose life traits can be categorized as being r-selected.
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A brand new country, named Neoland, has a growth rate of 4%. How many years will it take the population of Neoland to double?
A brand new country, named Neoland, has a growth rate of 4%. How many years will it take the population of Neoland to double?
Use the Rule of 72:
is rate of growth
is time (in years) it takes to double
By manipulating the equation to divide 72 by the given growth rate, you can find the number of years it takes for the population to double.
Use the Rule of 72:
By manipulating the equation to divide 72 by the given growth rate, you can find the number of years it takes for the population to double.
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Which of the following is a false statement regarding genetic mutations?
Which of the following is a false statement regarding genetic mutations?
Mutations occur at low rates. They are rare and not very common in most individuals. This explains why the process of evolution and adaptation occurs over long periods of time.
Mutations occur at low rates. They are rare and not very common in most individuals. This explains why the process of evolution and adaptation occurs over long periods of time.
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Which of the following factors affect birth rates?
Which of the following factors affect birth rates?
The use of child laborers leads to higher birth rates. More children are needed to support families and households. Educating women also decreases birth rates. This is the reason why developing countries tend to have higher birth rates than developed countries. A lower average marriage age leads to an increase in birth rates. Religion can influence birth rates, either raising or lowering (generally it raises the birth rate).
The use of child laborers leads to higher birth rates. More children are needed to support families and households. Educating women also decreases birth rates. This is the reason why developing countries tend to have higher birth rates than developed countries. A lower average marriage age leads to an increase in birth rates. Religion can influence birth rates, either raising or lowering (generally it raises the birth rate).
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A scientist observed a population of ants at a research site over the course of five years. He noticed that as the density of the population increased, the population growth rate began to stabilize over time. What ecology principle was the scientist observing with the ants?
A scientist observed a population of ants at a research site over the course of five years. He noticed that as the density of the population increased, the population growth rate began to stabilize over time. What ecology principle was the scientist observing with the ants?
The correct response is density dependence. Since the population growth rate is dependent on the size of the population, it is therefore regulated by density. This is the perfect example of a density dependent population.
The correct response is density dependence. Since the population growth rate is dependent on the size of the population, it is therefore regulated by density. This is the perfect example of a density dependent population.
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A scientist observed a population of leafhoppers at a research station in the Oak Openings region over the course of two years. She noticed that the only factor regulating the size of the leafhopper population was forest fires. Based on her observation, what ecological principle explains the growth rate of the leafhoppers?
A scientist observed a population of leafhoppers at a research station in the Oak Openings region over the course of two years. She noticed that the only factor regulating the size of the leafhopper population was forest fires. Based on her observation, what ecological principle explains the growth rate of the leafhoppers?
The correct response is density independence. The leafhopper population was not regulated by density. The only thing that regulated the population was abiotic events, such as forest fires.
The correct response is density independence. The leafhopper population was not regulated by density. The only thing that regulated the population was abiotic events, such as forest fires.
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