Carcinogens. They come in many forms (search them up) and can be very harmful.
Answer: cellular respiration reverses the overall photosynthetic reaction, but less efficiently. The useful energy output of respiration is less than the energy input required for photosynthesis.
Explanation:
overall photosynthetic reaction
Light energy + 6CO2 + 6H2O —> C6H12O6 + 6O2
cellular respiration
C6H12O6 + 6O2 —> 6CO2 + 6H2O + energy (as ATP and heat)
Traditionally, some textbooks from the United States used a system of six kingdoms<span> (Animalia, Plantae, Fungi, Protista, Archaea/Archaeabacteria, and Bacteria/Eubacteria) while textbooks in Great Britain, India, Australia, Latin America and other countries used </span><span>five kingdoms</span>