Eco practice 1

Which of the following descriptions about the organization of an ecosystem is correct?

• Communities make up species, which make up populations.

• Populations make up species, which make up communities.

• Species make up communities, which make up populations.

• Species make up populations, which make up communities.

In what way are herbivores and carnivores alike?

• They both use photosynthesis to make their own food.

• They both obtain energy by consuming other organisms.

• They both directly consume producers.

• They both are considered to be autotrophs.

What goes in Box 5 of the food web in Figure 3–2?

• herbivores

• scavengers

• carnivores

• decomposers

Organisms need nutrients in order to

• utilize hydrogen and oxygen.

• carry out essential life functions.

• recycle chemical compounds.

• carry out nitrogen fixation.

The movements of energy and nutrients through living systems are different because

• energy flows in one direction, and nutrients recycle.

• energy is limited in the biosphere, and nutrients are always available.

• nutrients flow in one direction, and energy recycles.

• energy forms chemical compounds, and nutrients are lost as heat.

Which is an example of how biotic and abiotic factors interact?

• Sunlight increases the temperature of pond water.

• Water and soil mix together to make mud.

• Tree roots split apart rocks in the ground.

• Humidity in the air forms fog in a valley.

Which of the following is a food chain in the food web shown in Figure 3–4?

• tree, rabbit, hawk, snake

• grass, grasshopper, snake, hawk

• grass, caterpillar, robin, hawk

• tree, deer, mountain lion, fox