Potometer works on the principle of :

1. Amount of water absorbed equals the amount transpired

2. Osmotic pressure

3. Root pressure

4. Potential difference between the tip of the tube and that of the plant.

Difficulty Level:

Which of the following in guard cell is responsible for opening of stomata?

1. decrease in $C{O}_{2}$ concentration and more ${H}^{+}$ ion

2. decrease in $C{O}_{2}$ concentration and less ${H}^{+}$ ion concentration

3. increase in $C{O}_{2}$ concentration and more ${H}^{+}$ ion concentration

4. More free ${H}^{+}$ ion and less $C{l}^{-}$ ion.

Difficulty Level:

Passive adsorption of water by the root system is the result of

1. Forces created in the cells of the root

2. increased respiatory activity in root cells

3. tension on the cell sap due to transpiration.

4. osmotic force in the shoot system.

Difficulty Level:

Water is lost in a liquid state in some plants through hydathodes. These hydathodes

1. remain closed at night

2. remain closed during day

3. remain always open

4. do not show any specificity in opening and closing.

Difficulty Level:

Which of the following statements are true/false?

a. the positive hydrostatic pressure is called turgor pressure.

b. wall pressure exerts to prevent the increase of protoplasm size.

c. diffusion is more rapid in liquids than in gases

d. diffusion of water through a semi-permeable membrane is called imbition

e. osmosis is movement of substances which takes place along a diffusion gradient.

1. a and b are true & c, d and e are false

2.  a and c are true & d, d and e are false

3.  a and d are true & b, c and e are false

4.  a and e are true & b, c and d are false

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Path of water movement from soil to xylem is :

1. soil$\to$ root hair$\to$ cortex $\to$pericycle $\to$endodermis $\to$metaxylem $\to$protoxylem

2. soil $\to$root hair$\to$ cortex$\to$ endodermis$\to$ pericycle $\to$protoxylem$\to$ metaxylem

3. soil $\to$root hair $\to$epidermis$\to$ endodermis$\to$ phloem$\to$ xylem

4. soil $\to$root hair$\to$ epidodermis$\to$cortex$\to$ phloem$\to$ xylem

Difficulty Level:

In land plands, the guard cells differ from other epidermal cells in  having :

1. Cytoskeleton

2. Mitochondria

3. Endoplasmic reticulum

4. Chloroplasts

Difficulty Level:

Turgor pressure is also referred to as

1. solute potential

2. water potential

3. pressure potential

4. osmotic potential

Difficulty Level:

In most species, as K+ moves in or out of the guard cell to regulate the stomatal opening, there is movement in the opposite direction by

1. Na+

2. H+

3. OH-

4. Cl-

Difficulty Level:

The opening of the stomata is effected by all of the following except

1. oxygen concentration

2. temperature

3. light

4. carbon dioxide concentration