Parenchyma tissue is the most common simple permanent tissue in plants. Why is it known as Chlorenchyma and Aerenchyma in some plants?

The correct answer is Chlorenchyma - Has chlorophyll photosynthesis (leaves), Aerenchyma - Has air spaces (aquatic plants) and helps them to float.

Key Points

• Sclerenchyma is found in the covering of seeds and nuts, veins of leaves, around the vascular tissues in stems. 
• Simple Permanent tissues: 
  • The tissues which are specialized to offer elasticity, flexibility, and strength to the plant but have lost their ability to distribute. 
  • Simple Permanent Tissue can be classified into the parenchyma, sclerenchyma, collenchyma, based on their purpose. 

Additional Information

• Parenchyma: 
  • These are living polygonal cells with a big central vacuole & intercellular spaces amidst them.
  • Parenchymatous cells are responsible to create ground pith & tissue.
  • It comprising of chloroplasts and that's why it is termed as chlorenchyma & it helps in photosynthesis.
  • Parenchyma which comprises of The big air voids is called aerenchyma. 'Buoyancy' is the main purpose of aerenchyma.
  • Some of these cells perform as storage chambers for starch in fruits & vegetables.
• Collenchyma: 
  • These have minute intercellular gaps & are stretched out living cells. 
  • Their cell walls are made up of cellulose & pectin.
  • Collenchyma is found in the marginal regions of stems & leaves.
  • It offers mechanical support in plants & offers flexibility with the structural framework.
• Sclerenchyma: 
  • In their cell wall, these are dead cells with lignin deposits
  • Sclerenchyma is found in the covering of seeds and nuts, veins of leaves, around the vascular tissues in stems. 
  • It provides strength to the plant & they have no intercellular gaps.