AP Environmental Science : Ecosystems and Biology

Study concepts, example questions & explanations for AP Environmental Science

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Example Questions

Example Question #3 : Reproductive Patterns And Principles

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 __________.

Possible Answers:

Asexual

K-selected species

Fungi

R-selected species

Correct answer:

R-selected species

Explanation:

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.

Example Question #12 : Population Ecology

Which of these animals is a K-selected species?

Possible Answers:

Turtle

Bullfrog

Elephant

Gerbil

Correct answer:

Elephant

Explanation:

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.

Example Question #4 : Reproductive Patterns And Principles

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?

Possible Answers:

Density independence

Bottleneck event

Exponential growth 

Density dependence 

Correct answer:

Density dependence 

Explanation:

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. 

Example Question #11 : Reproductive Patterns And Principles

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?

Possible Answers:

Metapopulation theory

Island biogeography

Density independence

Density dependence

Correct answer:

Density independence

Explanation:

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. 

Example Question #12 : Population Ecology

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?

Possible Answers:

The population will likely decline because the fact that the majority of the population are fifteen or younger indicates that something is killing the reproductive-age members of the population. 

Cyclical fluctuations will occur in the population because they are typical of a population with high fertility and mortality rates.

The population will remain constant, because high fertility rates paired with few people living to old age indicates a high fertility rate is needed to sustain the population. 

Exponential population growth fueled by high fertility rates and a large proportion of the population reaching reproductive age.

The population will decline because not enough individuals are surviving to reach reproductive age (i.e. war and disease are the diminishing factors). 

Correct answer:

Exponential population growth fueled by high fertility rates and a large proportion of the population reaching reproductive age.

Explanation:

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. 

Example Question #1 : The Human Population

Which of the following is FALSE regarding urbanization?

Possible Answers:

people's impact on the land is more pronounced in cities

people who live in urban areas consume less resources per capita

population growth rarely outstrips the growth of infrastructure

urban areas tend to be warmer than surrounding natural areas

urban sprawl is destroying natural habitat

Correct answer:

population growth rarely outstrips the growth of infrastructure

Explanation:

Often, the growth of cities is too fast for the construction of adequate infrastructure. This results in transportation problems, including traffic gridlock and longer commuting times. The other answers are true regarding urbanization. Cities have a number of environmental drawbacks and benefits.

Example Question #1 : The Human Population

Which of the following countries has a declining population?

Possible Answers:

Nigeria

United States

India

Ukraine

Philippines

Correct answer:

Ukraine

Explanation:

Ukraine, like many former Soviet Bloc countries, has a declining population due to political unrest. Nigeria, the Philippines, the United States and India all have increasing populations.

Example Question #2 : The Human Population

In Stage One of a demographic transition, a population:

Possible Answers:

a high birthrate, a low death rate, and a growing population

has a high birthrate, a high death rate, and a stable population

a low birthrate, a low death rate, and a stable population

a low birthrate, a high death rate, and a declining population

has a high birthrate, a high death rate, and a growing population

Correct answer:

has a high birthrate, a high death rate, and a stable population

Explanation:

In the first stage of a demographic transition, a population has a high birthrate, a high death rate, and a stable population. Technological development is low, and populations are controlled mainly by famine and disease.

Example Question #2 : The Human Population

Which of the following is the term that is best defined as the number of children a couple must have to replace themselves in a given population?

Possible Answers:

Zero population growth number

Demographic transition

Total fertility rate

Replacement level fertility

Correct answer:

Replacement level fertility

Explanation:

Replacement level fertility is the number of children required by a couple to replace them. Currently, in the United States, this number is just above two. This number accounts for infant mortality and varies by region.

Example Question #1 : The Human Population

How has the CITES Treaty (Convention on International Trade in Endangered Species of Wild Fauna and Flora) been helpful in protecting endangered animals and plants?

Possible Answers:

It lists those species and products whose international trade is controlled.

It funds projects for breeding endangered plants and animals.

It lists those species that can be hunted, traded, and used commercially.

It prevents the hunting of endangered marine life.

It specifies prices for endangered plant and animal products and byproducts.

Correct answer:

It lists those species and products whose international trade is controlled.

Explanation:

The CITES treaty is the Convention on International Trade in Endangered Species of Wild Fauna and Flora, and entered into force in July 1975. The treaty's aim is to ensure that international trade in wild animals and plants does not threaten the survival of such endangered species, listed in varying degrees of protection and applying to more than 35,000 species. Thus it monitors international trade as it pertains to all manner of protected wildlife. 

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