Do Now #5:  What do you think are the necessities of life? Does all life need oxygen to live?












Aerobic: -


Anaerobic: -
  

General Roots and Prefixes

Root or Prefix	Meaning	Examples
a, an	not, without	atheist, anarchy, anonymous apathy, aphasia, anemia, atypical, anesthesia

Was the first life on Planet Earth, aerobic or anaerobic and why?





Do you think life on Early Earth required water?


All organisms require water in some form, to either replace cells, tissue, or to reproduce. DNA requires water for replication.  Water is used in almost all metabolic reactions (digesting of food).  Plants need water to complete photosynthesis.

The overall chemical reaction involved in photosynthesis is:

6CO₂ + 6H₂O (+ light energy) C₆H₁₂O₆ + 6O₂.

If all life on the planet needs water then their must have been water present in Early Earth...during the Hadean Eon.

KEY CONCEPT: THE PRESENT IS THE KEY TO THE PAST. 

If it is true today then we assume it was true in the past.  Ex: if hurricanes cause tidal surges today, we can assume they caused tidal surges in the past.  If the moon causes tides today we can assume it caused tides in the past.  If life needs water to survive today then we can assume life needed water in the past.  If the chemical reaction for photosynthesis is  6CO₂ + 6H₂O (+ light energy) C₆H₁₂O₆ + 6O₂  then it was the same in the past.