question

give reasons : 

(a) cooking is faster in pressure cooker than in cooking pan.

(b) red blood cells (rbc) shrink when placed in saline water but swell in distilled water. 

 

 

 

 

 

 

 

 

 

(a) it is so because the pressure inside the cooker is high, as very less steam goes out. higher the pressure, higher is the boiling point. hence, the cooking is faster in pressure cooker.

(b) as the concentration of saline solution is higher than the concentration inside the cell. thus, water will move outside the cytoplasm and the cell will shrink, termed as plasmolysis or crenation. on the other hand, when rbc is placed in distilled water, water will enter the cell leading to swelling of the cell.