Chimeras are interesting organisms that have two different sets of DNA. Chimeras occur when two different zygotes fuse to form one organism. Some chimeras have no outward symptoms, while some have signs such as two different eye colors or two different blood types. This model shows how chimeras form. What roles do mitosis and meiosis play in the process?

it has one origin of replication, but it proceeds in two directions - d)

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.