Quarter 3 PSSA Review

Which statement best explains why a food web more completely represents the flow of energy through an ecosystem than a food chain does?

• More ecosystems have too many organisms to fit into a food chain.
• More energy flows through most ecosystems than a single food chain can show.
• Relationships between organisms usually change quickly enough to make food chains inaccurate.
• There are more relationships between organisms than can be shown in a single food chain.

How can an increase in the diversity of producer and decomposer populations most likely affect the stability of an ecosystem?

• Stability would increase because more light energy would be available.
• Stability would increase because more populations would be supported.
• Stability would decrease because fewer nutrients would be returned to the soil.
• Stability would decrease because less energy would be available to consumers.

A mouse’s habitat is a grassland containing rocks, soil, and grass. The mouse lives in a burrow underground. Based on this information, which statement best describes how the mouse interacts with its environment?

• The mouse uses soil for food and shelter.
• The mouse gets energy from its predators.
• The mouse changes its environment to create food.
• The mouse gets energy and shelter from its environment.

In the spring, some golden eagles fly north over Pennsylvania. In the fall, they fly back south for the winter. Which statement best describes why these golden eagles live in southern areas in winter?

• In northern areas, there is less food for eagles in winter.
• In northern areas, there are more competing birds in winter.
• In southern areas, there are fewer eagle predators in winter.
• In southern areas, there is more space for eagle nesting in winter.

Use the food web to answer the question. Which statement best describes sunlight and how it affects this food web?

• Sunlight is living and enters the food web through the hawk and the fox.
• Sunlight is living and enters the food web through the maple tree leaves.
• Sunlight is nonliving and enters the food web through the hawk and the fox.
• Sunlight is nonliving and enters the food web through the maple tree leaves.

In England before the industrial revolution, peppered moths were mainly white with black speckles, but a small group within the population had a genetic mutation that caused them to appear dark gray. After industrialization, the increase in air pollution caused tree bark to darken. Eventually, the lighter-colored peppered moths became less common than the dark-gray moths. Why did the population of moths change?

• Predators were easily able to see their prey.
• People hunted the lighter colored moths.
• White moths were killed by the smoke from factories.
• After industrialization the lighter colored moths used camoflage to avoid predation.

Which combination is a likely food chain?

• A.
• B.
• C.
• D.

The cycling of water from ocean surfaces to the atmosphere mainly depends on which process?

• evaporation caused by the Sun
• precipitation caused by the Sun
• evaporation caused by warm ocean currents
• precipitation caused by warm ocean currents

Which best represents evaporation?

• A
• B
• C

Which best represents transpiration?

• A
• B
• C