Lesson 4 -Ecosystems

Plants interact with living and nonliving components in their environment. Which is an interaction with a nonliving element?

• Small insects eating the stems of the plants
• Humans breathing oxygen released by plants
• Bees gathering pollen from flowers of plants
• Sandy soil holding the roots of the plants

Pacman frogs live in South America. Some of their traits are listed here.
What habitat change might be harmful for a Pacman frog?

• Heavy rains in the afternoons over a period of days
• An increase in population of several kinds of birds
• The introduction of a new species that eats rodents
• A change in weather, leading to cooler temperatures

Which adaptation of a cactus is related to its interactions with living organisms in its environment?

• roots that grow deep underground to reach water

• large, expandable stem that allows it to store water

• a waxy, outer coating to prevent the loss of the water

• spines to protect it from animals that want its water

Which of the following is a question that could be asked in a scientific investigation of how organisms depend on their environment?

• How does temperature affect the formation of soil?
• What time of day produces the most precipitation?
• What is the effect of rainfall on the growth of grasses?
• How fast does water erode different types of rock

All of the following are examples of living things interacting with each other EXCEPT —

• birds preying on insects living in the grass
• squirrels spreading the seeds of trees by burying them
• frogs sleeping in the mud at the bottom of the pond
• fish eating plants and other smaller fish

Many animals in an ecosystem depend on other animals for —

• air
• energy
• shelter
• water

Plants are interacting directly with another living element of their environment when they are - 

• soaking up water
• absorbing sunlight
• attracting insects
• taking in carbon dioxide

If sunlight could no longer reach the habitat shown, which of these would happen first?

• The fish in the lake would increase.
• The deer would get larger
• The grass would die
• The lake would dry up

Each time animals exhale, they are releasing ___________ gas into the air.

• methane
• carbon dioxide
• carbon monoxide
• calcium carbonate

A student observing animals in a park records ways they interact with living and nonliving parts of their environment.  All of the following are ways animals interact with nonliving parts of their environment except:

• A turtle suns itself on a hollow log.
• A bird reacts to morning sunlight by singing.
• A rabbit eats grass near the edge of a pond.
• A spider crawls under a rock for protection.