Anatomy Of Flowering Plants Class 11 Notes Biology Chapter 6 - CBSE

Chapter : 6

What Are Anatomy Of Flowering Plants?

Plant Tissues

Meristematic Tissue

(Immature cells capable of divisions)

  • Apical Meristem (Present at the growing tips of stems and roots responsible for increase in length)
  • Intercalary Meristem (Present at the bone of internodal regions, responsible for secondary growth)
  • Lateral Meristem (Present in lateral regions, responsible for increase in width of the plant)

Permanent Tissue

(Mature cells incapable of divisions)

Simple (Made up of only one type of cells)

  • Parenchyma
    (Living tissue stores and condusts food, water and minerals)
  • Collenchyma
    (Living tissue provides strength and flexibility to growing part of the plant)
  • Sclerenchyma
    (Dead tissue, provides mechanical support)

Complex (Protecting and supporting)

  • Xylem

    (Conducts water and mineral from the root to the steam and leaves)
  • Tracheids
    (Elongated tube like with thick lignified walls)
  • Vessels
    (Long cylindrical with lignified walls)
  • Fibres (Highly thickned walls)
  • Xylem parenchyma
    (Living cells, thin walled)

  • Phloem

    (Transport food from the leaves to the other parts) 

  • Sieve tube elements
    (Long, tube like, arranged longituinally)
  • Companion cells
    (Specialised parenchyma)
  • Phloem parenchyma
    (Long cylinrical, stores food)
  • Phloem fibre
    (Made up of sclerenchyma, thick cell wall)

Tissue System

Epidermal Tissue System

It includes cuticle, epidermis, epidermal hairs, root hairs, trichomes and stomata.

Ground Tissue System

It is made up of parenchyma, collenchyma, and sclerenchyma. In dicot stems and roots the ground tissue is divided into hypodermis, cortex, endodermis, pericycle, medullary rays and pith.

Vascular Tissue System

It includes vascular bundles which are made up of xylem and phloem.

Difference Between Tissue System In Dicots And Monocots

Dicot Root

  1. Xylem is usually tetrarch.
  2. Pith is usually absent.
  3. Metaxylem vessels are generally polygonal in cross section.
  4. Secondary growth is present.

Monocot Root

  1.  Xylem is polyarch.
  2. Pith is usually large at the centre.
  3. Metaxylem vessels are generally circular in cross section.
  4. There is no secondary growth.

Dicot Stem

  1. The dicot stem is solid in most of the cases.
  2. The hypodermis is formed of collenchyma fibres which are often green in colour.
  3. The internal tissues are arranged in concentric layers.
  4. The ground tissue is differentiated as endodermis, cortex, pericycle, medullary rays, pith, etc.
  5. The vascular bundles are formed as broken rings.
  6. Phloem parenchyma is present.
  7. Pith is well-developed.
  8. Epidermal hair may or may not exist.
  9. Vascular bundles are less in number and are of uniform size.
  10. The dicot stem does not have a bundle sheath on the outside of a vascular bundle.
  11. The dicot stems have trichomes.
  12. The vascular bundles always remain open, due to the presence of cambium within phloem and xylem.

Monocot Stem

  1. The monocot stem is usually hollow at the centre.
  2. The hypodermis is made up of sclerenchyma fibres and they are not green.
  3. There is no concentric arrangement of tissues.
  4. The ground tissue is the same and is composed of a mass of similar cells.
  5. The vascular bundles are scattered irregularly around the ground tissue.
  6. Phloem parenchyma is absent.
  7. Pith is not as well-developed in monocots (usually absent in most)
  8. Presence of epidermal hair.
  9. There are numerous vascular bundles of different sizes.
  10. The monocot stem has a sclerenchymatous bundle sheath on the outside of a vascular bundle.
  11. The monocot stems do not have trichomes.
  12. The vascular bundles are closed.