anatomy

Question 1

dicot root

Answer 1

1. outermost layer-epiblema or epidermis
2. unicellular root hairs present
3. cortex comprises of several layers of thin-walled parenchymatous cells with intercellular spaces
4. innermost layer of the cortex, comrpising of barrel shaped cells with no intercellular spaces-endodermis
5. the tangential and radial walls of the cell have water-impermeable waxy suberin in form of casparian strips
6. next to endodermis are thick-walled parenchymatous cells called pericycle
7. pith is v small or inconspicuous
8. parenchymatous cells lying in between xylem and phloem-conjunctive tissue
9. tetrarch-shows 2-4 xylem patches
10. exarch condition
11. everyt inside endodermis-stele
12. radial arrangement

Question 2

monocot root

Answer 2

1. all same
2. pith large and well developed
3. no secondary growth
4. polyarch (6+ xylem bundles)

Question 3

Monocot stem

Answer 3

1. scattered vascular bundles
2. conjoint and closed VB’s
3. pith inconspicuous
4. peripheral VB’s smaller than central VB’s
5. VB’s contain water containing cavities
6. phloem parenchyma is absent

Question 3

dicot stem

Answer 3

1. covered with a thin layer of cuticle, may bear trichomes and few stomata
2. cortex differentiated into-hypodermis-collenchymatous, cortical layers-rounded thin walled parenchymatous, and endodermis- parenchymatous cells rich in starch grain
3. pericycle present on inner side of epidermis-semi lunar patches of sclerenchymatous
4. between vascular bundles-few radially place parenchymatous cells-medullary rays
5. ring arrangement of vascular bundles
   6.conjoint, open, endarch condition of xylem
   7.large number of rounded parenchymatous cells-occupy central portion of stem-pith

Question 4

Dicot stem

Answer 4

• upper surface: adaxial epidermis; lower surface: abaxial epidermis
• ## abaxial has more stomata; adaxial may even lack stomata