Unit 6 Ecology/Biodiversity

Which is a biotic factor that could affect an ecosystem?

• dust storms moving through an ecosystem

• bacteria harming the health of organisms in an ecosystem

• large amounts of acid rain precipitation seeping into the soil in an ecosystem

• high levels of carbon dioxide entering the atmosphere within an ecosystem

The three global biomes in the table are home to different species of fox and members of the deer family.

Biome Temperature Range Precipitation (cm per year)Typical Plants Fox and Deer Temperate deciduous forest –30 to 30°C(–22 to 86°F) 75 to 150 oaks, maples, small flowering plants gray fox, white-tailed deer Boreal (coniferous) forest –40 to 20°C(–40 to 68°F) 30 to 90 fir, pine, sprucered fox, moose Tundra –40 to 18°C (–40° to 64°F) 15 to 25 low-growing plantsarctic fox, caribou (reindeer)

Of the three biomes, why would you expect tundra to have the fewest number of animals in each population?

• Shortest plants

• tallest plants

• least amount of food

• most rain

One biome includes bearberry, a short plant with small, waxy leaves, shallow roots, and flowers that bloom quickly in the short growing season. Another biome includes tall grasses that can survive fires due to roots that extend 6 to 7 meters deep during the long growing season. What is most likely true about the two biomes?

• They have the same temperature range but different rainfall ranges.

• They have the same temperature range and the same rainfall range.

• They are at different latitudes but have the same temperature range.

• They are at different latitudes and have different temperature ranges.

The table lists some ways that plants have adapted to survive in a desert biome.

Desert Plant Adaptations 1 Flowers open at night for pollination by bats. 2 Spines protect plants from consumers. 3 Needles lose less water than broad leaves in high temperatures. 4 Wide root structures help plants soak up water in rare rainstorms.

Which statements describe adaptations to biotic factors in a plant’s desert biome?

• 1 and 2

• 1 and 3

• 2 and 3

• 2 and 4

Which biome has the most vegetation?

• desert

• forest

• grassland

• tundra

Why is it important to conserve the biodiversity of Earth?

• to decrease the amount of global predator populations

• to decrease the stability of major global ocean currents

• to increase the stability of ecosystems during environmental changes

• to increase the amount of nonrenewable resources located in the lithosphere

Why is it difficult to create a terrarium ecosystem that will last a long time without human help?

• Terrarium ecosystems cannot get enough sunlight.

• Terrarium ecosystems cannot get enough oxygen.

• Ecosystems with few species are weak and unstable.

• All ecosystems require thoughtful human management.

The Waccamaw Drainage System is a system of interrelated coastal wetlands in southeastern North Carolina. Land-use modification and human population growth threaten these wetlands in a variety of ways. Scientific experts have recommended a number of management practices to protect the Waccamaw Drainage System. Which one of these recommendations would reduce stream bank erosion?

• encourage no-till agriculture near waterways

• remove downed trees from river channels

• dredge certain segments of the river

• plant shoreline buffer zones

How could the introduction of a nonnative species of plant affect an ecosystem in North Carolina?

• It could pollinate the native plant species, producing a disease-resistant species.

• It could reduce the competition for space and light with native plant species.

• It could take over the habitats of the native plant species.

• It could cause some insect species to destroy native plant species.

Coal ash is a byproduct produced when coal is burned for energy. Coal ash contains sand, unburned carbon, and a variety of metals, such as arsenic, cadmium, lead, mercury, and zinc. Some energy companies mix coal ash with water and store this waste in ponds. How could the accidental release of coal ash waste impact ecosystems?

• Heavy metals could bioaccumulate in aquatic food chains.

• Unburned carbon could enter waterways and provide food for organisms.

• Coal ash particles that mix with rain could acidify lakes and rivers.

• Leaking waste could increase blooms of toxic algae.