Answer:
if we`ll not classify living beings then it`ll become difficult to study all of beings one by one. In order to make their study easier biologists have classified all living beings into five major groups.
Explanation:
1) Pneumothorax in this case; a spontaneous pneumothorax can be life threatening cause the lung will eventually cause vacuum used by the lung to fill with air, and as you constantly expand your lung it decreases and collapses. So C is going to be the answer.
2) Acetylcholine is the hormone responsible for the "Rest and digest". It is the direct opposite of the Fight and Flight reaction which is marked in Bronchodilation, Increased HR, and increased BP. B
3) Secretin is responsible for stimulating the release of bile by the liver. Secretin is released by the duodenum, the junction of the stomach and small intestines. B
Explanation:
<u>the Paleozoic Era </u>
The Precambrian era describes a period of time that pre-dates Cambrian. This time typically references the entire period of the history of earth before the formation of rocks containing identifiable fossils occurred. It covers the majority of Earth’s history and is divided into the Hadean, Archean and the Proterozoic era.
Just before the Cambrian eruption, in the Paleozoic Era the environment was oxygenated, culminating in an explosion of new life in the Proteozoic Eon (2500-541 million years ago) in the form of primitive blue-green algae named cyanobacteria and oxygen based species. Multicellular species followed later, along with structure at higher levels, and complex life. Oxygen levels grew gradually over this period of time, from low levels.
Learn more about cellular life at brainly.com/question/11259903
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