Population Dynamics Environmental Systems

This graph is from a Yellowstone National Park ranger's field journal documenting changes in the size of the deer population. Which one of these 4 conclusions can be drawn from the section of the graph maked with an X?

• The carrying capacity will drop over time.

• The deer population has reached the carrying capacity of its environment.

• The deer population will decline and drop back to its original number.

• The carrying capacity has been severly reduced by drought.

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Certain natural selection pressures can cause genetic diversity within a species to decrease. What is the effect on a population when there is a decrease in the population's genetic diversity.

• The population will be less likely to find sources of food because all of the individuals in the population will be competing for the same types of prey.

• The population will be more likely to adapt to changes in the ecosystem over time because the genes that remain in the population are more likely to mutate.

• The population will have a greater chance of surviving when changes in the ecosystem occur because only those with genetic advantages will have survived.

• The population will be at risk if a new disease is introduced because a greater percentage of the population will have the same traits that make them more vulnerable to the disease.

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Dissolved oxygen (DO) concentrations are expressed as milligrams of oxygen per liter of water (mg/L). The amount of DO affects the types of aquatic life present in a body of water.

What would be the effect on the ecosystem if an algae population increased exponentially in a lake and caused the dissolved oxygen levels to decrease in the lake to near zero?

• The plant populations would decrease because they could not perform photosynthesis.

• The salt levels in the lake would increase causing the lake to no longer be a freshwater lake.

• The algae population would stop growing exponetially and maintain its population size at its carrying capacity.

• The heterotroph populations would decrease in the lake because they would not be able to perform respiration.

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Which graph accurately identifies the carrying capacity of a population?

• A

• B

• C

• D

Depletion of nonrenewable resources such as oil, gas, coal, minerals, or useable water is not likely to impact ―

• world food production

• demand for scarce resources

• global economic growth

• over population of countries

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NGSS.MS-ESS3-4

Kudzu, a fast-growing Asian vine, was imported to the U.S. in the 1930s to control erosion. It has smothered millions of acres of forests since then. In fact, most of the species on the U.S. endangered list are there, in part, because of invasive species like kudzu and its effects

on the environment.

Which statement is correct about these plants?

• Kudzu has been in the U.S. long enough to become a native species.

• Kudzu does not provide food and shelter for animals native to the forest biome.

• Kudzu is causing a change in the biodiversity of ecosystems.

• Bringing in another foreign species that eats kudzu will solve the problem.

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Observe the food web shown here. If the gray wolf became extinct, what conclusion about the coyote population would not be valid based on the relationships shown in the food web?

• The coyote population will decrease because the gray wolf is the coyote’s main competition for food sources.

• The coyote will become the apex predator and greatly reduce the populations of foxes.

• If another wolf is introduced to fit the same niche, the coyote population will decrease.

• As the number of coyotes increase, the number of beavers will decrease.

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Which of the following causes of death for a bird population can be linked to a density independent factor?

• Intestinal parasites

• Avian flu

• Hail storm

• Predators

Which of the following would increase due to high nitrate levels in the water of a lake ecosystem?

• Dissolved oxygen

• Long-term viability

• Biodiversity

• Organic matter

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A population of rabbits live in an area where there are plenty of resources, very few competitors for food, and limited predators.

Which graph best describes the growth pattern for this population of rabbits?

• A

• B

• C

• D

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