NCERT Solutions Class 11th Biology Chapter – 6 Anatomy of Flowering Plants
| Textbook | NCERT |
| class | Class – 11th |
| Subject | Biology |
| Chapter | Chapter – 6 |
| Chapter Name | Anatomy of Flowering Plants |
| Category | Class 11th Biology Notes |
| Medium | English |
| Source | last doubt |
NCERT Solutions Class 11th Biology Chapter – 6 Anatomy of Flowering Plants
?Chapter – 6?
✍Anatomy of Flowering Plants✍
?Notes?
Anatomically, a plant is made up of different kinds of tissues. Tissue is broadly classified into meristematic (apical, lateral, and intercalary) and permanent (simple and complex) tissues.
Tissues perform various functions such as assimilation, mechanical support, storage, and transportation of materials such as water, minerals, and photosynthates.
There are three types of tissue systems viz. epidermal ground and vascular.
The ground tissue system may be divided into three zones-cortex, pericycle, and pith.
The vascular or conducting tissue system includes the xylem and phloem.
Dicotyledonous and monocotyledons plants show marked variation in internal structures. They differ in the type, number, and location of vascular bundles.
Secondary growth occurs in most of the dicotyledonous roots and stems and it increases the diameter of the plant.
The wood is actually secondary xylem, which is formed during one growth session. There are different types of wood on the basis of their composition.
Meristems – Growth in plants is largely restricted to specialized regions of active cell division called meristems.
Apical meristems – The meristem which occurs at the tips of roots and shoots and produces primary tissues are called apical meristems.
Intercalary meristems – The meristem which occurs between mature tissues is known as the intercalary meristem
Primary meristem – Both apical meristems and intercalary meristem are also called the primary meristem.
Lateral meristem – The meristem that occurs in the mature regions of shoots and roots of many plants, particularly those that produce a woody axis and appear later than primary meristem is called the lateral meristem
Protoxylem – Primary xylem is of two types. The first formed xylem elements are called protoxylem.
Metaxylem – The later formed xylem is called metaxylem.
Endarch – In stems, the protoxylem lies towards the centre (pith) and the metaxylem lies towards the periphery of the organ, called Endarch.
Cuticle – The outside of the epidermis is often covered with a waxy thick layer which is called the cuticle.
Guard cells – Each stoma is composed of two bean-shaped cells known as the guard cells.
Subsidiary cells – Sometimes, a few epidermal cells, in the vicinity of the guard cells become specialized in their shape and size, known as subsidiary cells.
Stomatal apparatus – The stomatal aperture, guard cells, and the surrounding subsidiary accessory cells are together called stomatal apparatus.
Trichomes – The cells of the epidermis bear a number of hairs known as trichomes.
Mesophyll – In leaves, the ground tissues consists of thin-walled chlorenchyma and is called mesophyll.
Open vascular bundles – The xylem and phloem together constitute vascular bundles. Such vascular bundles are called open vascular bundles.
Radial – When xylem and phloem within a vascular bundle are arranged in an alternate manner on different radii as in the roots are called radial as in the roots.
Epidermis – The outermost layer is the epidermis.
Endodermis – The innermost layer of the cortex is called the endodermis.
Conjunctive tissue – The parenchymatous cells which lie between the xylem and phloem are called conjunctive tissue.
Mesophyll – The tissue between the upper and the lower epidermis is called the mesophyll
Bulliform cells – In grasses, certain adaxial epidermal cells along the veins modify themselves into large, empty, colourless cells, which are called bulliform cells.
Secondary growth – Apart from primary growth most dicotyledonous plants exhibit an increase in girth. This increase is called secondary growth.
Springwood or earlywood – The wood formed during this season is called springwood pr earlywood.
Autumn wood or latewood – In winter, the cambium is less active and forms xylary elements. These have narrow vessels, and this wood is called autumn wood or latewood.
Annual ring –The two kinds of woods appear as alternate concentric rings, constituting an annual ring.
Cork cambium – Sooner or later, another meristematic tissue called cork cambium or phellogen.
Periderm – Phellogen, phellem, and phelloderm are collectively known as periderm.