Energy Flow & Nutrient Cycles

Why is the sun's energy necessary for the water cycle?

• it is the heat source that turns water into vapor

• it is the light source that turns water into vapor

• it is the source that turns vapor into water droplets

How do living organisms return carbon to the atmosphere in the carbon cycle?

• respiration and photosynthesis
•  decomposition and respiration

Which of the following removes carbon from the atmosphere?

• Combustion
• Respiration
• Photosynthesis
• Death

Gas that makes up almost 80% of Earth's atmosphere

• oxygen
• carbon dioxide
• nitrogen
• hydrogen

Use the diagram to answer the question.
The Mayfly is a food source for which 3 organisms?

• Frog, Dragon Fly and snake
• Frog, trout and dragon fly
• Frog, salamander and trout
• Frog and phytoplankton

What gas is released by plants during photosynthesis?

• sulfur
• carbon dioxide
• oxygen
• hydrogen

If there is 1000 Kcal available in the producers in trophic level 1, how much energy is available in the herbivores in trophic level 2?

• 10 Kcal
• 1 Kcal
• 100 Kcal
• 1000 Kcal

In this food web, which two organisms could be harmed if the mouse population were to decrease?

• Deer and caterpillar
• Wolf and snake
• Oak and grass
• Hawk and songbird

Most of the nitrogen on earth is atmospheric nitrogen gas. Nitrogen gas cannot be used by most life. What process converts it into usable nitrogen and which organisms do this?

• Predation, wolves

• Digestion, all animals

• Nitrogen Fixation, bacteria

• Denitrification, bacteria

The efficiency of energy transfer from a lower trophic level to the next highest level is roughly

• 1%
• 10%
• 100%
• 1000%