Population and Community Ecology (Unit 8 Standard B)

A population of 250 birds inhabit the canopy of a tropical rain forest that has a carrying capacity of 400 birds.

What is the maximum population growth rate  (rmax)  if the population grows to 283 in one year?

• 0.12

• 0.13

• 0.35

• 0.39

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NGSS.MS-LS1-5

A fish population of 250 in a pond has a maximum annual rate of increase of 0.8. If the carrying capacity of the pond is 1,500 for this species, what is the expected population size after one year?

• 167

• 417

• 450

• 500

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NGSS.HS-LS2-1

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The population of Japanese sika deer in central Japan was determined each year from 2005 to 2014. The sika deer population underwent logistic growth starting at 26,000 deer in 2005 and stabilized at 58,000 deer between 2012 and 2014. Based on these data, the  rmax  for this population was determined to be 0.57. Central Japan contains a variety of habitats, including forests and grasslands. Sika deer benefit from the resources in grasslands more than forests; if deforestation occurred, producing more grasslands in the region, the carrying capacity for sika deer population would increase.

What would the population size of sika deer be one year after the carrying capacity increased to 70,000 as a result of deforestation? Assume  rmax  does not change.

• The population would grow to 70,000 deer in a year, because they would occupy the entire environmental niche.

• The population would grow to 91,060 deer in a year, but then they would die off from a lack of resources.

• The population would grow to 63,667 deer in a year, and the growth rate would decrease the following year.

• The population would remain at 58,000 deer, since it had already stabilized.

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NGSS.MS-LS2-1

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Which point on the curve in the diagram above best represents the carrying capacity of the environment for the population shown?

• A

• B

• C

• D

• E

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NGSS.MS-LS2-4

All of the following are density-dependent factors that limit animal populations EXCEPT

• weather

• predation

• birthrate

• food competition

• mortality

Scientists studying a wild population of mantled howler monkeys found the average birth rate to be  0.22  and the average death rate to be  0.12 . At the start of the study, the population consisted of  13  monkeys.

Assuming no immigration or emigration, which of the following best describes the change in population size that will occur over the next year?

• The population size will decrease because a population of  13  is too small to sustain itself.

• The population will decrease because more monkeys are dying each year than are being born.

• The population will increase exponentially because it is so small that there are likely few competitors and abundant resources.

• The population will increase because more monkeys are being born each year than are dying.

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NGSS.MS-LS2-1

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Researchers studied the diversity of macroscopic invertebrates in different areas of watershed ecosystems. They collected samples from 58 sites along 11 streams in the same geographical area. Their data were classified by stream type and can be found in Figure 1. The stream-type classifications range from the perennial stream type, which always has water, to the intermittent stream type, which is dry for more than nine months during the year. Which of the stream types had a statistically lower macroscopic invertebrate species diversity than the seasonal streams?

• Transitional streams only

• Intermittent streams only

• Perennial and intermittent streams only

• Transitional and intermittent streams only

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NGSS.MS-LS2-1

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Interactions among populations determine how they access resources within a community. In Costa Rica, two different species of mites, Rhinoseius colwelli and Rhinoseius richardsoni, exhibit a high degree of interspecies competition. Both mite species live within the flowers of plants, and adult male mites tend to kill mites if they belong to a different species. An experiment was carried out to determine whether these aggressive interactions have resulted in niche partitioning by R. colwelli and R. richardsoni, of different flower species, with each mite species living in different plant species. The results are summarized in Figure 1. Which of the following is an accurate interpretation of the data in Figure 1 ?

• R. richardsoni is found significantly more frequently on Species 4 compared to Species 3.

• R. colwelli is found significantly more frequently on Species 1 compared to Species 2.

• R. richardsoni is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2.

• R. colwelli is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2.

Tags

NGSS.MS-LS2-1

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In the Florida Everglades, Burmese pythons are an invasive species. They were introduced into southern Florida in 1992. These pythons feed on many of the native Florida species, establishing the pythons as the top predator in the environment. By the year 2000, their population had increased dramatically.

Figures 1 and 2 display data collected by ecologists studying the results of the Burmese python invasion. Figure 1 shows counts of animals collected from nighttime road surveys in southern Florida, which are used to estimate population size. Figure 2 shows data collected from mosquitoes captured from the wild.  DNA  sequencing was used to identify the species of blood that the mosquitoes had in their stomachs, identifying various hosts used by the mosquitoes. In 1996, the native Culex cedecei mosquitoes in southern Florida preferentially took blood meals from white-tailed deer and raccoons. It was predicted that changes in host population size would alter these host preferences. Additionally, it is known that cotton rats are often infected by the Everglades virus, which normally exists in animals, but is capable of infecting humans. Ecologists predict that increased feeding on cotton rats by C. cedecei may significantly increase the tendency of this virus to infect humans.

Which of the following populations have significantly decreased in size between 1996 and 2011 ?

• White-tailed deer only

• Cotton rats and rabbits only

• White-tailed deer and raccoons only

• White-tailed deer, raccoons, and cotton rats

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NGSS.MS-LS2-1

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