Question

The apoplast does not hold true which of the following statements?

• A. Not continuous path at the place of casparian strips of the endodermis in the roots
• B. Occurs through the intercellular spaces and the walls of the cells
• C. Crosses cell membrane
• D. System of adjacent cell walls that is continuous throughout the plant

Answer 1

The correct option is C Crosses cell membrane

The apoplast pathway comprises of non-living components of a plant body i.e., intercellular spaces and cell wall. The movement through apoplast is unregulated and fast. Symplast comprises of living components i.e., protoplasm, cell membrane and plasmodesmata.

Water potential or free energy of water depends on the number of water molecules in the system. More the number of water molecules greater will be water potential. When solutes are dissolved in water, there is a decrease in relative number of water molecules and this causes corresponding decrease in water potential. Membrane permeability depends on the nature of biological membrane and the nature of solutes. The membrane is composed of phospholipids and proteins.

Consequently lipophilic substances can freely pass through the membrane, while hydrophilic substances cannot freely pass through the membrane and require special carrier or transport proteins for transport across the membrane.