13D Environmental Change Quiz 1

Kelp forests are critical ecosystems that provide habitats to many animals and also provide hunting grounds for mammals, including sea otters. In recent years scientists have documented an increase in shark attacks on sea otters in and around kelp forests.

Which consequence is most likely to occur in kelp forests as a result of increased predation of sea otters?

• Kelp forests will become more stable due to the decrease in otter predation pressure.

• Kelp forests will become more stable as sharks replace otters as the top predator in the food chain.

• Kelp forests will become less stable due to the increase in the size of the otters' prey populations.

• Kelp forests will become less stable as sharks will also eliminate the prey of the otters.

Tags

TEKS.BIO.13.D

Giant salvinia is a floating fern native to Brazil introduced to Texas as an aquarium plant and is now found in large bodies of water across the state. The invasive plant may be carried to new bodies of water by fishing and recreational boats. It grows quickly, covering large areas of the water's surface. When the plant dies and decays, the oxygen content in the water declines.

Which statement BEST describes how giant salvinia affects a Texas ecosystem?

• It promotes the growth of new types of plants.

• It increases the stability of the ecosystem.

• It provides an energy source for the ecosystem.

• It inhibits the growth of native plant species.

Tags

TEKS.BIO.13.D

Purple loosestrife is an invasive flowering plant species now found in North America. In an effort to control the purple loosestrife, biologists tested and released three beetle species to use as a biological control of the plant.

Which result is an unintended negative consequence of releasing these beetle species into the environment?

• There will be an increase in the available habitat for non-native plant species.

• There will be an increase in the population numbers of native beetle species in the habitat.

• There will be an increase in competition for food resources among all beetle species in the habitat.

• There will be an increase in pollination of native flowering plant species.

Tags

TEKS.BIO.13.D

East Texas has a wide variety of frog species that take advantage of different resources in the ecosystem, by eating different foods, choosing different ponds, and mating at different times of the year.
How does the biodiversity of frog species MOST LIKELY affect the stability of the ecosystem?

• By making the ecosystem more vulnerable to population losses

• By increasing the ecosystem's ability to stay healthy when conditions change

• By reducing the ability of individual organisms to adapt to changing conditions

• By making individual organisms less vulnerable to competition from invasive species

Tags

TEKS.BIO.13.D

The population of an invasive crab species, Callinectes sapidus, is rapidly increasing along coastal Europe. This aggressive, fast-growing omnivore reproduces quickly and is causing the extinction of many native species.

Which statement BEST describes the effect of a native species' extinction on local ecosystem biodiversity and stability?

• Extinction leads to decreases in biodiversity and decreases stability.

• Extinction leads to increases in biodiversity and decreases stability.

• Extinction leads to increases in biodiversity and increases in stability.

• Extinction leads to decreases in biodiversity and increases stability.

Tags

TEKS.BIO.13.D