13 a
14. At which location would a person experience the longest number of daylight hours answer B
Facilitated diffusion is usually significant to pass the ions across the hydrophobic layer of the plasma membrane. Transmembrane integral protein and careers proteins provide the channels that allow the ion to pass across the membrane. When an ion bind to their active site on the protein (note that the proteins are very selective), the protein changes conformation. It is this change in conformation opens up the channel that allows the ions to be passed across the membrane. When the ions are released inside of the cell, the protein resumes normal shape (and the channel also closes) and the active site becomes available again or another ion.
Answer: The cell membrane is selectively permeable.
Explanation: going thru last year notes
Answer:
The function of the pleura is to allow optimal expansion and contraction of the lungs during breathing. The pleural fluid acts as a lubricant, allowing the parietal and visceral pleura to glide over each other friction free. This fluid is produced by the pleural layers themselves.