Question

The airway epithelial cells maintain a thin layer of watery liquid containing salt. Their cilia beat in the watery liquid to move mucus and particles out of the airway and into the back of the throat, where it is swallowed into the digestive tract. To maintain salt balance, the CFTR channel opens to allow Cl- ions to diffuse across the cell membrane and into the airway liquid. In the absence of CFTR function, the airway liquid becomes hypotonic. Which way will water molecules flow?

from the surrounding cells into the airway

from the airway into the cells that line the airway

there will be no net movement of water into or out of the airway

The airway epithelial cells maintain a thin layer of watery liquid containing salt. Their cilia beat in the watery liquid to move mucus and particles out of the airway and into the back of the throat, where it is swallowed into the digestive tract. To maintain salt balance, the CFTR channel opens to allow Cl- ions to diffuse across the cell membrane and into the airway liquid. In the absence of CFTR function, the airway liquid becomes hypotonic. Which way will water molecules flow?

from the surrounding cells into the airway

from the airway into the cells that line the airway

there will be no net movement of water into or out of the airway The movement of chloride ions through the plasma membrane would be best described by which of the following lines? a b

Answer 1

When CFTR function is absent and the airway liquid becomes hypotonic, then water molecules will from the airway into the cells that line the airway.

Note :

Hypotonic airway means there will be less ion in the airway as compared to the cells lining the airway. Thus , water will move towards cells via osmosis.