(50 points + ! )what did the miller-urey experiment demonstrate?
earth's early atmosphere contained abundant oxygen.
early earth was constantly bombarded with comets.
small organic molecules formed from gas mixture of earth's early atmosphere.
organisms were spontaneously generated on early earth.

Option C  

Explanation:

Miller and Urey performed an experiment, using some inorganic molecules such as water, methane, carbon dioxide and hydrogen in laboratories conditions similar to early earth conditions .

Amino acids molecules formed as the result of this experiment, this proved that small organic molecules such as amino acids are formed from inorganic molecules.

Hence, the correct answer is option C  

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.