Match the letter with the term

a. nitrogen

b. trace gases

c. ozone (in upper atmosphere)

d. carbon dioxide

e. oxygen

1. this gas is essential to the nutrition of plants and animals; present in all proteins and dna in all organisms; acts to dilute atmospheric oxygen to prevent uncontrolled combustion.



2. this gas is used by all living things; essential for respiration; necessary for combustion or burning.



3. plants use this gas in photosynthesis to make oxygen; prevents some infrared heat loss from earth's atmosphere.



4. neon, helium, krypton, and xenon - don't do much



5. this gas absorbs and scatters ultraviolet light preventing it from reaching the surface.