Lesson 4: Nitrogen Cycle

Multiple Choice

What number is nitrogen on the periodic table?

• 8
• 6
• 14
• 7

Multiple Choice

Which of the following are basic building blocks in cells that require nitrogen?

• DNA and proteins

• Carbohydrates and fats

• Vitamins and minerals

• Water and oxygen

Multiple Choice

Which processes are carried out by bacteria to convert nitrogen into forms usable by plants?

• Nitrogen fixation and nitrification

• Photosynthesis and respiration

• Transpiration and evaporation

• Fermentation and digestion

Fill in the Blanks

The process by which bacteria convert nitrogen gas back to the atmosphere is called

.