Carbon and phosphorus cycles — practice questions

Question 1 · difficulty L1 · recall

Which process removes carbon dioxide from the atmosphere and incorporates it into organic matter?

• A. Cellular respiration
• B. Photosynthesis
• C. Decomposition
• D. Combustion

Question 2 · difficulty L3 · application

Why is the phosphorus cycle described as largely sedimentary rather than gaseous?

• A. Plants release phosphorus directly as a gas
• B. Phosphorus is stored mainly as carbon dioxide
• C. Most phosphorus circulates as nitrogen gas
• D. It has no major atmospheric reservoir

Question 3 · difficulty L3 · understanding

The amount of nutrients such as carbon, nitrogen, potassium and calcium present in the soil at any given time is referred to as :

• A. Standing state
• B. Standing crop
• C. Humus
• D. Detritus

Question 4 · difficulty L3 · understanding

Which one of the following will accelerate phosphorus cycle?

• A. Burning of fossil fuels
• B. Volcanic activity
• C. Weathering of rocks
• D. Rain fall and storms

Question 5 · difficulty L3 · understanding

The amount of nutrients, such as carbon, nitrogen, phosphorus and calcium present in the soil at any given time, is referred as :

• A. Standing crop
• B. Climax
• C. Climax community
• D. Standing state

Question 6 · difficulty L5 · analysis

A lake receives excess phosphate from runoff for many years. Which change is most likely to alter the phosphorus cycle within the lake?

• A. More phosphate enters biomass and sediments
• B. Rapid conversion of phosphate into atmospheric gas
• C. Complete elimination of decomposers
• D. Permanent stoppage of nutrient uptake by producers