practice questions

Stage where woody plants compete with non-woody plants for light

Stage where woody plants compete with non-woody plants for light

C. Shrubs

Stage that represents the greatest biodiversity

D. Hardwood trees

Stage that is dominated by only light tolerant species with an r-selected strategy

A. Annual Plants

Stage that is represented by nonwoody groundcover that can return year after year.

B. Perennial plants and grasses

The pH at which the perch can survive but the salamanders cannot

C. pH 4.5

the most acidic pH found in this ecosystem

D. pH 4.0

the pH at which all species can survive

A. pH6.0

What best explains the change in mosquito resistance over time, as shown by the previous data?

D. Both communities have the same species richness, but community 1 has greater species evenness.

Which of the following best describes why primary succession occurs before secondary succession?

A. Primary succession establishes soil in the area.

A model is shown of a series of stages in a forest community. Which of the following most likely describes the fire and the subsequent stages?

B. This is secondary succession and the community will recover more quickly than if it were primary succession.

According to the theory of island biogeography, what condition promotes the acceleration of the extinction rate of species on an island?

A. The island is small and far from the mainland.

Which of the following would promote a species adapting more quickly to environmental change?

B. having a short generation time

Which of the following best describes the author's claim in the article?

D. Ecosystems with biodiversity provide services to humans which may be lost without conservation.

Which ecosystem service mentioned in the article supports the claim that ecosystems offer provisioning services?

C. medicine

According to the article, what would be the best solution to mitigate biodiversity losses?

Conserving areas of greater biodiversity

Which of the following can be concluded from the information in the graph?

D. Carbon dioxide fluctuations are a natural part of Earth's history.

What explains the changes in species in response to the changes in Earth's climate over the past 400,000 years?

C. Species that were adapted to the changes in climate survived with greater frequency.

Which of the following best explains the changes in the coyote ranges over the past 300 years?

A. As habitat destruction increases, coyotes are becoming more adapted to areas with greater urbanization

Four islands and their relative positions to the mainland are shown above. Which island would be predicted to have the species type and distribution that is most similar to the mainland?

A. Island A

Ecologists are researching the biodiversity of the four islands by sampling the tree and bird species that are found on each of the islands and comparing those to that of the mainland. What are the independent and dependent variables in this investigation?

B. The independent variable is the different islands and the dependent variable is the species diversity.

Developers remove the majority of trees adjacent to a river ecosystem. Which of the following explains how the fish in the river may be affected?

D. Fish adapted to greater light levels and warmer temperatures will increase in number.

Examine data for two different communities of 100 organisms.
Community A: Ten species with 10 species each.
Community B: Five species with the following individual distributions: 40, 25, 15, 10, and 10

What can be inferred about the two communities?

A. Community A has a higher species richness than Community B

Which of the following statements about genetic diversity is true?

B. Breeding programs using organisms outside of the typical gene pool can increase genetic diversity of crops and domesticated animals.

Which of the following is the best description of species evenness?

D. The relative dominance of each species within an ecosystem

Which explanation BEST describes the origin of the biodiversity of vertebrates, as shown in the phylogenetic tree here?

D. Differing selective pressures shaped populations that diverged into different groupings.

Examine the table here showing the number of individuals of each species found within four field communities. based on the data, which community has the greatest biodiversity?

C. Community 3

Which of these hypotheses is supported by the data shown in the previous question?

D. Community 4 has a higher biodiversity than community 2 because it has an equivalent species richness but a higher species evenness

According to the data in the table for the four communities, which community has the highest species richness but lowest species evenness?

B. Community 2

Loblolly pine requires a minimum temperature to grow and thrive. It is currently a prominent conifer species in the Southeastern United States. If average temperatures increase throughout the United States due to climate change, which of these predicts the change to the distribution of loblolly pines?

B. species will spread north and have an increased range.

Which of the following explains why small isolated islands have a greater rate of species extinction than larger, less isolated islands?

D. Small isolated islands have a lower availability of resources and a decreased colonization.

A simplified marine food chain is shown above. It depicts the energy transfer between kelp, sea urchins, sea otters, and killer whales. When killer whales were introduced, they preyed upon the sea otters, causing sea otter populations to decline. What best explains the role of the sea otter in the ecosystem shown above?

A. Sea otters are a keystone species because, in their absence, the producer level of the food chain is diminished.

Population biologists are concerned about introduced species such as the zebra mussel in North America because

The introduced species compete for resources more effectively than native species causing a reduction in biodiversity.

Over 12,000 years ago at the end of the last ice age, the Laurentide Ice Sheet began melting and retreating in North America. The melt water and glacial erosion created glacial lakes across the northern half of the United States. Following the formation of a glacial lake, algae and phytoplankton in the lake begin to grow and reproduce rapidly. Which of these best matches the description here?

B. Primary succession

Madagascar and the Seychelles are both islands in the western Indian Ocean. Madagascar is over 1,000 times larger than the Seychelles. Using the theory of island biogeography an ecologist would predict that

A. there is greater species richness on Madagascar.

In an area with low biodiversity during primary succession, which species would likely be a pioneer species among the bare rock?

B. Lichen

Members of a town committee are asked to determine the borders for a new local nature park. In order to promote the maximum biodiversity and species richness in the park, which of the following measures should be implemented?

B. The distance between the park and a nearby protected forest should be decreased.

Which of the following shows the process of evolution best?

D. A population of weeds develops resistance to herbicides over time.

Describe TWO characteristics shared by ecosystems that have high biodiversity

(1) large number of species (2) large number of individuals (3) complex food webs (4) greater genetic diversity (5) variety of ecological roles/niches
(6) abundant resources

Identify TWO specific human activities that result in a loss of biodiversity, and explain how each activity lowers biodiversity.

(1) clearing land: reduces habitat for many species (2) agriculture: eliminates native species, decreases genetic variation, and eliminates beneficial organisms (3) overfishing/hunting/poaching: reduces keystone species, apex predators, depletes endangered species

For each human activity you discussed in (b), propose a practical strategy (other than simply banning the activity) to reduce the loss of biodiversity.

(1) clearing land: cluster development, smart growth planning (2) agriculture: require GMO crops to be sterile (3) overfishing/hunting/poaching: regulate activities and/or establish quotas, enforce laws, ban trade

Describe ONE naturally occurring factor that could lead to a loss of biodiversity.

(1) widespread wildfires can wipe out small populations (2) hurricanes wipe out coastal nursery areas (3) Droughts (4) mutation/evolution may lead to new diseases/predators

Describe TWO ecological benefits that greater biodiversity provides.

(1) pollination (2) water/air filtration (3) control of pest species (4) more source material for evolution (5) soil microorganisms can contribute to nutrient recycling