Year 10 Biogeochemical Cycles Revision

The following chemical process represents:

• the Carbon Cycle

• Photosynthesis

• Cellular respiration

• the Water Cycle

Nitrogen gas accounts for what percentage in the atmosphere?

• 1%

• 17%

• 65%

• 78%

What is the first step in the nitrogen cycle, in which gaseous nitrogen is converted into ammonia?

• Nitrification

• Ammonification

• Assimilation

• Nitrogen fixation

Transpiration occurs in:

• oceans.

• ground water.

• animals.

• plants.

The major source of dissolved oxygen in the ocean comes from

• Decomposition of organic sediments on the ocean floor.

• Respiration by zooplankton

• Photosynthesis by phytoplankton

• The conversion of liquid water to vapor during evaporation

Green plants do not grow in oceans at depths greater than about 80 metres.  Which of the following statements BEST accounts for this fact?

• The ocean is too cold at this depth

• Insufficient sunlight penetrates beyond this depth

• The ocean currents are too strong below 80 metres

• There is insufficient mineral content in waters below this depth

The raw materials needed for photosynthesis are:

• Oxygen and sugar 

• Water and carbon dioxide

• Carbon dioxide and oxygen

• Water and oxygen

Consider the following diagram and identify the missing words in order for A, B, C, D

• Photosynthesis, animal respiration, decay, combustion

• Plant respiration, animal respiration, decay, combustion

• Respiration, excretion, decay, combustion

• Decay, respiration, excretion, combustion

A shift of only a few degrees Celsius in the average global temperature will likely result in more frequent and extreme heat waves. Which of the following choices best describes this phenomenon?

• Habitat destruction

• Weather change

• Climate change

• Ozone formation

The following diagram represents the nitrogen cycle in nature. The process represented by the arrow marked X would be:

• Fixing atmospheric nitrogen by root nodule bacteria

• Assimilating atmospheric nitrogen by lightning

• Nitrogen dissolving in rainwater

• The addition of nitrogen compounds to improve the soil