How can a robin have a ddt concentration of 444 ppm even though the soil contains only 10 ppm of ddt

Robin can have a ddt concentration of 444ppm while the ddt concentration of soil is 10 ppm. This happens due to biological magnification.

Explanation:

In biological magnification the concentration of toxic substances at successive trophic levels keeps increasing. Due to biomagnification, what starts out as a small concentration grows  while moving to successive trophic levels. DDT is a pesticide which is used to kill pests that affect crops.

DDT used in farms gets deposited in the soil. From the soil it can reach various trophic levels. At each trophic level its concentration keeps increasing.

Robin is a bird that is a secondary consumer and thus belongs to the higher trophic level. Thus even if the DDT concentration is as low as 10ppm in the soil its concentration will keep increasing and can become a high value like 444ppm.

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.