Vascular Bundles Structure and Classification (Different Types of Vascular Bundles): Plant Anatomy by Easybiologyclass

1. .: _L ; ,f , <w‘, , 2-. — , 1«i» - ‘ wiscumla BUN LES Structure & Classiﬁcation «————*——-————-——_——; —+—'—~—’-V-—'—»-— ~———. — ——~= =-. '——————_? ’~ '— *—- —u , , . —= ——— *—. j—-’ e—mail: easybiologyclass@gmail. com " mail@easybiologyclass. com www. easybiologyclass. c0m '

2. ”It is not so much that the cells make the plant; it is rather that the plant makes the cells" Heinrich Anton de Bary www. easybiologyclass. com ls)

3. Learning objectives: I What are vascular bundles (VB)? I How Vascular bundles originate? I Different types ofvascular bundles in plants: I Conjoint VB I Collateral VB I Bi-collateral VB I Open and Closed VB I Radial VB I Concentric VB (amphicribral and amphivasal) www. easybiologyclass. com

4. VASCULAR BUNDLES What are vascular bundles? What are its components? I Vascular bundles are components of Vascular Tissue System I Also called as ‘fascicle' 1 Part of TRANSPORT system in plants _, j *4 » 3' l 3' g Bundle I One of the PRIMARY tissue system in plants I It is a COMPLEX tissue system in plants tesmaa saw 4 - . On. dﬁiof 3 Fpeﬂole lg‘: -is2ee. ~za. ena; sa'sn*: §su ' I Complex tissue = composed ofMORE THAN ONE TYPE OF CELLS www. easybiologyclasscom 4

5. VASCULAR BUNDLES 7' [A51 What are vascular bundles? What are its components? Vascular bundles consists of TWO main parts I ‘C ”/ ‘x. _ _ I‘ I‘ ‘ _ 1. Xylem: water conducting tissue - ’ l 1 . " 2. Phloem: food conductingtissue : cg ' r j . , -vw. :mhinl ~§l€%n , Xylem and phloem are complex tissues Typical Vascular gumue Components of xylem: Tracheids, Vessels, Xylem fibres & Xylem parenchyma Components of phloem: Sieve cells, Sieve tube elements, companion cells, Phloem parenchyma, Phloem fibres (bast fibres) www. easybiologyclass. com Ul

6. VASCULAR BUNDLES How vascular bundles originate in plan ts? E The elements of xylem and phloem are always organized in groups called VASCULAR BUNDLES W" H " W Vascularﬂundle X. /I’ _/ ' bundles www. easybiologyclass. com 6

7. VASCULAR BUNDLES g j E Z ‘(EASY ‘ Different types of vascular bundles: 1 Vascular bundles are classified based MANY criterions 1. Based on presence of Cambium/ secondary growth > Open VB & Closed VB 2. Based on arrangement in the plant body > Radial & Conjoint 3. Based on arrangement of individual VB components > Collateral, Bi-collateral & Concentric (amphicribal & amphivasal) www. ea. sybiologyclass. com 7

8. VASCULAR BUNDLES Different Types of Vascular Bundles Open Closed Vascular Bundle (VB) Tl Radial Conjoint I Collateral I Bi-collateral Concentric Amphicribal Amphivasal www. easybiologyclass. com

9. VASCULAR BUNDLES Open & Closed Vascular Bundles: I A classification of VB based on presence of Cambium I Cambium: a meristematic tissue responsible for secondary growth Phloem (1). Open vascular bundle Cambium > Cambium present between xylem & phloem Xylem Secondary growth present > Open Vascular Bundle_ ‘ > Characteristic of dicotyledons (dicots) > Open for secondary growth V’ Cambium present between xylem & phloem is called FASCICULAR CAMBIUM 7 _ ~ » Open VascularBune(Dicot'Stem) @

10. VASCULAR BUNDLES Open & Closed Vascular Bundles: Phloem (2). Closed vascular bundles: I Cambium absent within vascular bundle x"'°"' I Secondary growth absent Closed Vascular Bundle . . um I Characteristic of monocotyledons [monocots) I Closed for secondary growth I Fascicular Cambium absent Closed Vascular Bundle (Monocot Stem) E

11. VASCULAR BUNDLES Radial Vascular bundle I Based on the arrangement of VB components I Xylem and phloem are arranged separately I Arranged alternatively in different radii I Radial vascular bundles are found in ROOTS Xylem Phloem Radial Vascular Bundles ﬂ

12. VASCULAR BUNDLES "% I r IASV BIOLOGY CLASS Conjoint vascular bundles I Xylem and phloem are arranged together I Xylem and phloem in same radius I Conjoint VB are found in STEM and LEAVES I Three types: 1. COLLATERAL 2. BI-COLLATERAL 3. CONCENTRIC

13. VASCULAR BUNDLES (1). Collateral vascular bundles: I A type of conjoint VB I Phloem located ONLY OUTSIDE of the xylem I Xylem towards interior, phloem towards exterior ‘~'i~ . 45+ Collateral Vascular Bundles I Most common type I Collateral VB may be Open or Closed Phloem Phloem Cambium Cambium Xylem Xylem Open Vascular Bundle Open Vascular Bundle Collateral Vascular Bundles Q

14. VASCULAR BUNDLES , _ ‘n EASY IIOLOCY (MM (2). Bi-collateral Vascular Bundles Phloem I A type of conjoint VB I Phloem present in two groups Xylem I One outside the xylem, other inside the xylem Phloem I (xylem in the middle, phloem both sides) I Characteristic of some Angiosperms Bi-collateral vascular Bundle I Example: members of Cucurbitaceae (Cephalandra, C ucurbita) I Bi-collateral vascular bundles are always OPEN

15. VASCULAR BUNDLES (3). Concentric Vascular Bundles: A type of conjoint vascular bundle One VB element completely surrounds the other Either phloem surrounds xylem or xylem surrounds the phloem Two types: a) Amphicribal: b) Amphivasal: www. ea. sybiologyclass. com UI

16. VASCULAR BUNDLES (3). Concentric Vascular Bundles: A). Amphicribal: F A type of concentric vascular bundle VA. “~l n Xylem lies at the centre, surrounded by a ring of phloem A, ,,, m'/ .1,a1 r“. Example: Meristeles of ferns, small vascular traces of ﬂowers, fruits and ovules B). Amphivasal: r" A type of concentric vascular bundle F Phloem lies at the centre, surrounded by a ring of xylem Amphivasal F‘. Example: Dracaena stem, Rumex, Begonia www. easybiologyclass. com 1 6

17. 43.. V‘ '7' , 1:: ' K. /PIASY H VASCULAR BUNDLES Model questions: What is meant by collateral vascular bundle? What is meant by bi-collateral vascular bundle? Differentiate open and closed vascular bundles? What is meant by concentric vascular bundles? What is meant by radial vascular bundles? Describe bi-collateral vascular bundle. Give example. What is amphicribal vascular bundle? Give one example. What is amphivasal vascular bundle? Give one example. . ‘°. °°. l. °‘. °": F‘S'°E"! " What are the components of vascular bundle? 10. How vascular bundles are classified based on secondary growth? 11. Write a short note on concentric vascular bundles with examples. 12. Differentiate collateral and bi-collateral vascular bundles. www. easybiologyclass. com 17

18. VASCULAR BUNDLES Reference: Prakash, E. I. I. , A Text Book of PlantAnatomy, Ed. 2, 2000, Emkay Publications, Delhi. wwweasybiologyclass. com 18

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