Conjoint, Bicollateral Concentric and Amphicribral Concentric and Amphivasal ii. Cortex: It is multilayered large zone, composed of parenchymatous cells with intercellular spaces. It stores water and food material. iii.
Endodermis: It is the innermost layer of cortex with characteristic casparian strips and passage cells. Casparian strips are band like thickening made of suberin . iv. Stele: All the tissues inner to endodermis constitute stele.
It includes pericycle, vascular tissues and pith. a) Pericycle: It is a single layer of thin walled cells. The lateral roots originate from this layer. b) Vascular tissues: It consists of many patches of xylem and phloem arranged radially.
The xylem is exarch and polyarch. The conjunctive tissue is made up of sclerenchyma. c) Pith: It is present at the center. It is made up of parenchyma cells with intercellular spaces.
It contains abundant amount of starch grains. It stores food. . Internal Structure of Dicot Stem (Sunflower) The transverse section of a dicot stem reveals the following structures.
. Epidermis: It is the outermost layer. It is made up of single layer of parenchyma cells, its outer wall is covered with cuticle. It is protective in function.
. Cortex: - It is divided into three regions: (i) Hypodermis: It consists of - layers of collenchyma cells. It gives mechanical support. Figure .
Transverse section of Dicot root A sector enlarged Ground plan Root hair Xylem Phloem Cortex Piliferous layer Pericycle Casparian strip Conjunctive tissue Phloem Endodermis Passage cell Root hair Piliferous layer Cortex Xylem Figure . Transverse section of Monocot root A sector enlarged Ground plan Root hair Piliferous layer Cortex Endodermis Pith Root hair Piliferous layer Casparian strip Endodermis Pericycle Phloem Xylem Pith Cortex Plant Anatomy and Plant Physiology (ii) Middle cortex: It is made up of few layers of chlorenchyma cells. It is involed in photosynthesis due to the presence of chloroplast. (iii) Inner cortex: It is made up of few layers of parenchyma cells.
It helps in gaseous exchange and stores food materials. Endodermis is the inner most