1.

• Two organisms interacting
• An organism interacting with a nonliving component of its ecosystem
• Two organisms competing for space
• A producer helping another producer

2.

• Two organisms competing for food
• A producer helping another producer
• An organism interacting with a nonliving component of its ecosystem
• An organism depending on another organism for energy

3.

• A consumer interacting with a producer
• A producer helping another producer
• An organism interacting with a nonliving component of its ecosystem
• An organism depending on another organism

4.

• Different species competing for food
• Organisms using nonliving components of their environment for food
• Organisms using nonliving components of their environment for shelter
• Organisms using living components of their environment for shelter

5.

• Carbon dioxide
• Wind
• Predators
• Oxygen

6.

• Carbon Dioxide
• Oxygen
• Plastic
• Sunlight

7.

• A hermit crab inside a shell
• A bird nesting in a tree hollow
• Rabbits consuming grass
• A tree producing acorns

8.

• Carbon Dioxide
• Seeds, berries, and insects
• Oxygen
• All of the above

9.

• Mushroom
• Meadow Lark
• Hawk
• Milkweed

10.

• Example 1 only
• Example 2 only
• Example 1 and 3 only
• Examples 1, 2, and 3