The primary reason surplus carbohydrates in plants are stored as starch is because: the space they occupy as carbohydrates is needed for other macromolecules. if they were left as individual monosaccharides, water would enter the cell by osmosis. all of these choices represent equally important reasons why surplus carbohydrates in plants are stored as starch. they would otherwise be utilized as energy sources even if such energy were not needed at that time. energy is needed in the nucleus, and only starch is capable of being transported into the nucleus.

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.

hi~~

i would say that hybridization occurs frequently in nature, because there are many types of hybrids that have occurred naturally, such as the mule (male donkey + female horse)