5.1 Science Savvas End of Topic: Interactions in Ecosystems

1. Look at the prairie food web. If a drought comes, things change. These steps in the cycling of matter are likely to occur.

The steps are not in order. Which answer shows these steps in the correct order?

A. Decomposers break down more dead matter.

B. Grasshoppers and jackrabbits have no food. Their populations decrease.

C. Without water, grass cannot produce its own food and dies.

D. Rattlesnakes have less food and begin to die off.

• Without water, grass cannot produce its own food and dies.

• Rattlesnakes have less food and begin to die off.

• Grasshoppers and jackrabbits have no food. Their population decreases.

• Decomposers break down more dead matter.

2. Rain is normally a rare event in this desert, but this year, the winter brought twelve extra days of rain. Now, spring has come. Groundwater is plentiful. The sun beams down, and all producers are growing and blooming.

Look at the image of the prairie ecosystem.

Which of these statements predicts how energy is flowing in the desert after the rains? Choose all that apply.

• A. More energy will flow from coyotes down to rattlesnakes.

• B. More energy will flow upward from producers to primary consumers.

• C. More energy will flow into the food web through thermal energy (heat).

• D. More energy will flow upward as animals eat other animals.

3. Rain is normally a rare event in this desert, but this year, the winter brought twelve extra days of rain. Now, spring has come. Groundwater is plentiful. The sun beams down, and all producers are growing and blooming.

Look at the image of the prairie ecosystem.

Which of these statements predicts how the increased rainfall will cause changes in how matter will cycle in this desert ecosystem?

• A. The producers will make less food. Consumers that eat plants or other animals will not have enough food.

• B. The consumers will make more food. Producers will get this food by eating plants or animals.

• C. The producers will make more food. Consumers will get this food by eating plants or animals.

• D. The consumers will make less food. Producers that eat plants or other animals will not have enough food.

4. Human activities can have a harmful effect on any ecosystem. Sometimes, humans use up resources, such as lumber or fossil fuels. At other times, human activities pollute the land or water. Sometimes, these activities are planned, such as building roads that fragment an ecosystem. At other times, mistakes are made, such as the introduction of invasive species. Invasive species are organisms that are not native to an ecosystem. They can be brought to new ecosystems intentionally or accidentally by humans. For example, many invasive species come to new ecosystems from cargo ships. These invasive species often have no predators, and they may reproduce faster than native species. They also eat the food resources that native species need to survive.

Part A
Which of these describes a healthy ecosystem that has been harmed by human activity?

• 
  

• A. A cottonfield is planted with soybeans to renew the soil.

• B. Zebra mussels, an invasive species, reproduce quickly and eat large amounts of algae that native species need for food.

• C. An animal overpass is built over a highway to allow deer, raccoons, and armadillos to cross without injury.

• D. Autumn olive trees, an invasive species, provide food for local birds.

4B. Which sentence describes a healthy ecosystem that has been harmed by humans?

• A. The high school basketball team uses individual bottles of water for every game.

• B. Alex grows his own tomatoes and peppers in the community vegetable garden.

• C. A group of scouts takes a nature hike and makes a list of birds they see along the trail.

• • 
    D. Mrs. Lopez's class plants a bee-friendly garden to help bring back honeybee populations to San Antonio.

5. 5. Look at the image of a tide pool ecosystem. A tide pool is an ecosystem on the edge of an ocean, sea, or bay. It is made of living and nonliving parts. The rocks, water, and air are ​ (a)   of a tide pool. The kelp, crab, and starfish are ​​ (b)   that depend on the rocks and water to survive.

• abiotic factors
• biotic factors
• producers 
• consumers

6. Soil is a mixture of abiotic and biotic materials.

Sort the biotic and abiotic components of soil by dragging each word to the correct box.

Groups:

(a) Abiotic Factors

,

(b) Biotic Factors

• worms

• rock

• dead wood

• air

• ants

• water

7. Which of these statements describes a healthy ecosystem?

• A. By 1880, nearly all bison were gone from the Great Plains, but deer, antelope, and ferrets had large populations.

• B. Weeds cover a pond, blocking out the sunlight. Producers in the pond cannot grow their own food without the Sun.

• C. A company plants 500 seedlings in a forest where many trees were cut down for lumber.

• D. A small pond supports a range of fish, frogs, plants, and a beaver family.

8. 8. In the night sky, bats fly through the dark. At the same time, mosquitoes swarm by the thousands. Bats are the (a)   and mosquitoes are their (b)   .

• prey
• predator
• primary consumer
• producer

9. Which of these describes how human activity can damage the abiotic factors in an ecosystem?

• A. A paper company filters all industrial runoff to reduce pollution in the river that runs by their plant.

• B. The face of a large rock is eaten away by acid rain caused by air pollution.

• C. A hillside collapses after heavy rain, sending rocks and soil crashing onto a road.

• D. A four-lane highway runs through a forest breaking up deer and elk habitats.