The correct option is B.
Communication between cells can be inter communication or intra communication. Inter communication refers to a type of communication in which message is transfer from a near or distant cell to another cell, while the intra communication form of message transfer is one in which a message is been passed across within a single cell.
In the option B above, a single cell is involved and that is an example of an intra communication. The other options are example of inter communication.
Hydrogen has two atoms in water, and there is one atom of oxygen in water
That statement is false because cells work together
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: D. Hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
Hypothesis A and B both are suggesting that caffeine intake is related to higher heart rate. But hypothesis B is proving it more certainly by suggesting the affects of caffeine intake on heart rate. As, heart rate of most people will be higher 30 minutes after they drink a cup of coffee is testifying the fact, that higher heart rate is related with caffeine intake.
Therefore, hypothesis B is more useful because it suggests a way to test the relationship between heart rate and caffeine intake.
