<span>Answer:During expiration, the volume of the thorax decreases as the diaphragm rises/relaxes.
In expiration the air gets out of the lungs and it's not occupying as much space in the lungs, so the volume of the thorax will decrease. Meanwhile, the diaphragm can go to his relaxed stage and move </span><span><span>superiorly</span>
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Natural levels of nitrate in Minnesota groundwater are usually quite low (less than 1 milligram per liter [mg/L] of nitrate-nitrogen). However, where sources of nitrate such as fertilizers, animal wastes, or human sewage are concentrated near the ground surface, nitrate may seep down and contaminate the groundwater. Elevated nitrate levels in groundwater are often caused by run-off from barnyards or feedlots, excessive use of fertilizers, or septic systems.
Wells most vulnerable to nitrate contamination include shallow wells, dug wells with casing which is not watertight, and wells with damaged, leaking casing or fittings.
Nitrate contamination of a well is often regarded as a first sign of deteriorating groundwater quality.
Answer: A. Nitrogen
Explanation: Nucleic acids contain the same elements as proteins: carbon, hydrogen, oxygen, nitrogen; plus phosphorous (C, H, O, N, and P). Nucleic acids are very large macromolecules composed of repetitive units of the same building blocks, nucleotides, similar to a pearl necklace made of many pearls.
Prokaryotes are the Earth`s firs living things. This are the simplest life forms exhibiting ( showing ) cellular structures.
They exist in 2 major forms:
- Eubacteria ( most of the common bacteria that are found everywhere ),
- Archaebacteria ( ancient bacteria that live in very extreme conditions ).
Answer: Prokaryotes.