Question

Circle only the statement that is false for each question:

1. The cells of withered plants have

(a) lost H2O (c) taken salt
(b) lost turgidity (d) been plasmolysed

2. Stems & leaves of wilted plants have:

(a) become flaccid (c) taken salt
(b) lost their turgidity

3. By placing these plants in pure H2O, they resume their turgidity because

(a) H2O enters the cells by osmosis (b) salt in the cells goes out by washing H2O

4. This movement of H2O occurs because

(a) [salt] in the cells increased (b) [salt] in the medium increased

Answer 1

1. c. Taken salt

Lost water, lost turgidity and plasmolysed refers to the same process. When cell losses water, they get plasmoysed (the cell membrane and cytoplasm shrinks). Taking in salt would affect the concentration of the cell but cannot lead to plasmolysis. Osmosis is seen here and not diffusion.

2. c. Taken salt

Loss of turgidity simply means the cell is flaccid.

3. Right statement: a. Water enters into the cell by osmosis

False statement: b. Salt in the cells go out by washing H2O.

When water moves out it shrinks the cell and the cell dies. Therefore plasmolysed cells have less chance of regaining turgidity, but a flaccid cell can become healthier when placed in water.

4.Right statement: Salt in the cell increased. This increases the concentration of the cell. As per the rule of osmosis, the water from its higher concentration (dilute solution) move to its lower concentration (concentrated solution).

False statement: Salt in the medium increased.