Quiz: Biogeochemical Cycles

1. Which is not an essential element to life on Earth?

A. Carbon B. Nitrogen

C. Boron D. Oxygen

2. Which of the following is not true about matter in the biosphere? A. Biogeochemical cycles transform and reuse molecules B. Biogeochemical systems use up matter as they change it C. Matter is recycled in the biosphere D. Water and nutrients pass between organisms and the environment

3. Bacteria are some of the smallest yet most important organisms on earth. As decomposers, they play a significant role in cycling nutrients within Earth’s ecosystems. Which is true of bacteria?

A. Bacteria only decompose dead organisms in the soil.

B. Bacteria do not decompose dead organisms in frozen areas.

C. Decomposers like bacteria turn once-living organisms into proteins for use in the food chain.

D. Bacteria decompose organisms into nutrients which are used by other organisms in the food chain.

4. Which would decrease the amount of carbon dioxide in the air the most? A. growing maple tree B. burning a forest

C. a person driving a car D. a running dog

5. Suppose humans modified the carbon cycle by burning more fossil fuels. Which statement offers the best prediction?

A. The animals would increase their rate of respiration.

B. The amount of carbon dioxide in the atmosphere would decrease.

C. The amount of carbon dioxide in the carbon cycle would increase.

D. The extra carbon dioxide would support more photosynthesis by plants. 6. The image above shows that the phosphorus cycle is similar to the oxygen and nitrogen cycles. Which is an important difference between the phosphorous cycle and the other biogeochemical cycles?

A. Phosphorus is not an essential nutrient for living things.

B. Phosphorus never enters the atmosphere as a gas.

C. Organisms can create their own phosphorus.

D. Plants absorb phosphate through their roots.