During self pollination in seed plants pollen grains

Self-pollination takes place when the pollen from the same plant arrives at the stigma of a flower or at the ovule. There are two kinds of self-pollination, that is, autogamy and geitonogamy.

In autogamy, pollen is moved towards the stigma of the similar flower. While in geitonogamy, pollen is moved from the anther of one flower to the stigma of another flower on the similar flowering plant, or from microsporangium to ovule within a monoecious gymnosperm.

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.