The oxidation of organic compounds by molecular oxygen to produce CO2 and water releases free energy because electrons are being moved from atoms that have a lower affinity for electrons.
Every protein has in itself molecular parts that function like zip codes and are used to designate where the protein must travel.
The endosymbiotic theory states that eukaryotic cells might have evolved from prokaryotic cells through a close realtionship.
Answer:
D fleas affect all animals