Alveolar walls are thin to enable the quick passage of oxygen in and out of the lungs. The lungs works hand-in-hand with the heart and also is responsible in converting blood that's de-oxygenated into an oxygenated blood that is usable by the organ systems of the body. The alveolar walls are also designed to have thin membranes so that it can expand and constrict quickly allowing us to breather properly.
Answer:
correct option is A.
Succession is the process by which the structure of a particular community evolves over a specific period of time. There are two types of succession, primary and secondary succession. Primary succession is a type of succession that occurs in a place which is incapable of sustaining the growth of plants, that is, it usually occur on barren lands. All the options given above are examples of places for primary succession with the exception of option A.
1) a decrease in the amount of groundwater.
Speciation is not a mechanism of microevolution.
The tundra has little variation in temperatures
