Answer:
Option C, Intrapleural pressure is less than intrapulmonary pressure
Explanation:
During inspiration, the air enters the lungs due to lower pressure in the intrapulmonary or intra-alveolar than the atmospheric pressure. During quite respiration, the intrapulmonary pressure reduces to a pressure that is 3 mm Hg lower than that of atmospheric pressure. During quiet expiration, the intrapulmonary pressure rises up to a pressure that is 3 mm Hg higher than that of atmospheric pressure. This leads to lack of air in the intrapleural space thereby producing intrapleural pressure which is lesser than that of intrapulmonary pressure.
This difference in pressure (i.e higher pressure with in the lungs than the atmosphere) causes lungs to remain attached to the chest wall and hence looks inflated.
Hence, option C is correct
Answer:
Option-C
Explanation:
Scientists found a fossil of a fish with four limbs or legs. The fossil was estimated to be around 375 million years old.
The fossil showed the fins and scales of a fish but they also possess the bones of proto-wrist, shoulders and the elbow.
The presence of these bones can be a clue that the fish evolved the limbs to walk on the land and will later evolve into animals belonging to amphibians, reptiles and mammals. Therefore, the Tiktaalik is considered the missing link of how life evolved from water to land.
Thus, Option-C is correct.
Answer:
A. As a young naturalist, Charles Darwin traveled around the world and made many discoveries on a small British navy ship, HMS Beagle.
