Igneous rocks are formed . A. when magma cools and solidifies
B. when the minerals in metamorphic rocks become calcified
C. by extreme temperatures and pressures
D. when the minerals in sedimentary rock react with acidic compounds in the ground

the peripheral nervous system or pns contains the nerves, which leave the brain and the spinal cord and travel to certain areas of the body. the peripheral nervous system's main job is to send information gathered by the body's sensory receptors to the cns as quickly as possible.

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.