Test Review

The arrows in the food chain point in this direction to show -

• How an organism transforms during its life cycle

• The flow of chemical energy between organisms

• What each organism eats

• How radiant energy increases the size of organisms

A habitat that receives less than 20 cm of precipitation each year and ranges in temperature from cold to very hot would be most suitable for small mammals that

• Are active during the day and feed on a variety of tree leaves

• Hibernate for many months of the year

• Are active at night and use water efficiently in their bodies

• Are covered in thick fur for warmth and insulation

Increased biodiversity in an ecosystem is seen as a positive indicator by biologists, because more species in an area - 

• Improves the productivity of farmers' crops.

• Prevents competition between organisms of the same species.

• Improves the stability and complexity of the food web.

• Stabilizes the climate and prevents natural disasters.

Select TWO of the following statements that correctly explain why oak trees don't typically grow in the temperate grasslands of North America. [choose TWO choices]

• The grasslands don’t get enough rain to support trees and sometimes experience drought.

• The grasslands are frozen for 8-10 months of the year, and the soil has permafrost 25 cm below the surface.

• Wildfires and grazing animals in the grasslands make it hard for trees to get established and survive.

• The soil in the grasslands is poor in nutrients and too acidic for trees to grow.

The arrows in the food chain point in the direction to show -

• The flow of chemical energy between organisms

• What each organism eats

• How radiant energy increases the size of organisms

• How an organism transforms during its life cycle

In the tropical wetlands of the Florida Everglades, invasive Burmese pythons are changing the ecosystem and causing biodiversity to decrease. These invasive snakes have established a large, reproducing population and their range has expanded quite far. The pythons are linked to large declines in several mammal populations in the Everglades. A 2012 research study showed that populations of raccoons in the Everglades had decreased 99.3%, opossums 98.9%, and bobcats 87.5% over a 15-year time span. Rabbits and foxes had essentially disappeared. These mammals have been regularly found in the stomachs of the Burmese pythons.

How is the Burmese python a threat to biodiversity in the Florida Everglades?

• The pythons are causing many mammals to starve by eating all of their food sources.

• The pythons are quickly eating so many mammals that their populations can’t rebuild.

• The pythons are destroying the habitat and forcing many mammals to leave the area.

In the tropical wetlands of the Florida Everglades, invasive Burmese pythons are changing the ecosystem and causing biodiversity to decrease. These invasive snakes have established a large, reproducing population and their range has expanded quite far. The pythons are linked to large declines in several mammal populations in the Everglades. A 2012 research study showed that populations of raccoons in the Everglades had decreased 99.3%, opossums 98.9%, and bobcats 87.5% over a 15-year time span. Rabbits and foxes had essentially disappeared. These mammals have been regularly found in the stomachs of the Burmese pythons.

How will the decrease in biodiversity affect the ecosystem of the Florida Everglades?

• The sustainability of the ecosystem will not be affected much; it will remain stable and productive.

• The ecosystem will become less sustainable and more vulnerable to a decline in productivity.

• The ecosystem will become more sustainable and less vulnerable to a decline in productivity.

High biodiversity improves the sustainability of an ecosystem, because –

• The ecosystem will continue to function even if some populations decrease.

• It makes the food web simpler and ensures there are very few predators.

• Many organisms will undergo beneficial mutations and improve their traits.

• It allows organisms from different species to mate and create new species.

A rotting log on the forest floor provides a microhabitat where organisms such as

______________

can spend much of their lives in safety and find the food and moisture they need.

• Woodpeckers and owls

• Insects, spiders, and small amphibians

• Bears and coyotes

• Squirrels and Rabbits

Students were studying bushes found in deserts and grasslands. They found that some bushes with yellow flowers looked very similar, but when looking at the leaves, they noticed small differences. The creosote bush is found in deserts and has small leaves with a thick waxy coating. The St. John’s wort bush is found in cooler climates and has small leaves that are much thinner and appear to have much less waxy coating. What explains this difference?

• The plants grow in different environments and have adapted to the climates they grow in.

• The plants use photosynthesis differently, so their leaves have different amounts of chloroplasts.

• There are different chemicals involved in photosynthesis for each plant, resulting in the changes.

• The plants are exposed to different amounts of sunlight, so the leaves have changed to produce more flowers.