Which of the following causes enlargement and extension growth of cells? 

The correct answer is Turgor pressure.

Key Points

• Enlargement and extension growth of cells is primarily caused by cell turgor pressure and cell wall expansion.
• In plants, this growth is driven by water uptake, which increases turgor pressure within the cells, leading to expansion.
• Additionally, the synthesis of new cell wall materials allows for cell elongation.
• Other factors, such as hormonal regulation (e.g., auxins), also play a role in promoting cell growth and elongation.

Additional Information

• Imbibition
  • It is the process by which a substance (usually a solid, like seeds or plant tissues) absorbs water and swells.
  • This occurs due to the affinity of water molecules for the polar surfaces of the solid. In seeds, imbibition triggers metabolic activities, leading to germination.
  • Example: When dry seeds are placed in water, they absorb water, swell, and become turgid, preparing for germination.
• Pressure Potential
  • Pressure potential is the physical pressure exerted by the fluid (usually water) within the cell against the cell wall.
  • In plant cells, when water enters the cell through osmosis, it creates turgor pressure that pushes the plasma membrane against the cell wall, contributing to the overall water potential.
  • Pressure potential is essential for maintaining cell structure and rigidity, allowing plants to stand upright and grow.
• Osmotic Pressure
  • It is the pressure required to prevent the flow of water across a semipermeable membrane due to osmotic potential (the tendency of water to move into a solution).
  • It results from differences in solute concentration on either side of a membrane. Water moves from an area of lower solute concentration (higher water potential) to an area of higher solute concentration (lower water potential).
  • It is crucial for processes like nutrient uptake, cell hydration, and overall water balance in cells and organisms.