Plant Organs and Functions

Plant Organs and Tissues

• A tree can be divided into different organs, including roots, stems, leaves, and flowers.
• Each organ has a unique origin, structure, and function.

Functions of Plant Organs

• Roots hold the tree in place and absorb water and mineral salts from the soil.
• Leaves produce food through photosynthesis.
• Stems transport water and mineral salts from roots to leaves and distribute food to other organs.

Tissues

• A tissue is a group of similar cells that originate from the same source and perform the same function.
• The main reason for tissue formation is division of labor among body-forming cells.

Classification of Tissues

• There are two main types of tissues: meristematic tissue and permanent tissue.

Meristematic Tissue

• Meristematic tissue is composed of cells that continuously divide, leading to growth in length and breadth.
• Features of meristematic tissue:
  • Cells are living, small, and isodiametric.
  • Cells are capable of division.
  • Cells are generally rectangular, oval, pentagonal, or hexagonal.
  • Cells have thin cell walls composed of cellulose.
  • Nucleus is large and dense, with granular cytoplasm.
  • No cell vacuole is present.
  • Cells are densely arranged with no intercellular spaces.
  • Metabolic rate is high, and cells are always in an active metabolic state.
  • No reserved, secreted product or waste is present inside cells.
  • Plastids remain in a proplastid state.
  • Cells are usually small, with almost equal length and breadth.
  • Meristematic tissue is composed of immature cells.
  • Cells divide by mitosis process.