4. Meristems
-enables plants to have
indeterminate growth
Apical meristems –tip of roots
and shoots
-initiate primary growth in the
length of roots and shoots
Primary Plant Body
Lateral/Secondary Meristem
Secondary Growth
4
12. Outer protective
covering (physical
damage desiccation)
Begins as parenchyma
cells then modifies
Helps control the
exchange of gases and
water vapor
Epidermis
Periderm
Cuticle
12
15. Makes up the plant’s bulk
Cortex
-between dermal and
vascular tissues
*storage of food
Pith
-between phloem and
xylem
-soft spongy parenchyma
cells
*nutrient storage and
transport
http://extension.oregonstate.edu/mg/botany/im
ages/fig3-big.gif
http://en.wikipedia.org/wiki/Pith
15
17. Raven, P.H. , Evert, R.F. and Eichhorn, S.E. 1999.
Biology of Plants 6th Ed. W.H. Freeman and Co.
Worth Publishers, USA. 944 pp.
Nabors, M.W. 2004. Botany an Introductory
Approach. Pearson Education South Asia Pte.
Ltd. 626pp.
Diola, A., Dy., D., Ilano, A., Inoc, D.C., Oquinena,
K., Parilla, R., Tambuli, A. and Yee, J. 2010.
Natural Science 1 (Biological Sciences) Lecture
Notes. University of San carlos, 126 pp.
Starr, C. 2003. Biology: Concepts and
Applications, 5th ed. Brooks/Cole, USA. 799 pp.
17
Notas del editor
Shoot System – upper part
Stem- supports upright growth; conduction of substances
Leaves –photosynthesis
Flowers –reproductive structure that attracts pollinators
Root System – specialized; penetrates soil (except for few); spread downward and sideward
Function: absorb water and dissolved nutriets; anchorage; stores food
Primary plant body –produced by shoot and root apical meristem
Primary meristems –regions of cell growth
Protoderm –produces the primary dermal tissue system or epidermis
Procambium –produces the primary vascular system (phloem, xylem)
Ground system –produces the ground or fundamental tissue system (neither conducting and dermal tissues)
Lateral meristem –makes plants woody; causes thickening of stems and roots
Secondary growth –growth in thickness produced by lateral meristems
Meristematic Cells –unspecialized cells that can divide indefinitely to produce new cells
Meristems –regions that produce new growth
Initials –meristematic cells that remain within meristems as sources of new growth; one of the daughter cells
Derivative –other daughter cell that is pushed out of the meristem divides or begins elongation and differentiation
Differentiation –process where an unspecialized cell becomes a specialized cell
with secondary walls hardened by lignin
-more expensive to produce (cellulose making up the secondary walls)
-less common in smaller plants
-typically dead in maturity
*provides rigid support
Types:
Fibers
Sclereids (stone cells) –rockhard and inflexible (nutshell and fruit pits); gritty sand-like structures (pears
Vascular plants –with highly organized and efficient vascular tissues consist of cells joined into tubes that transport water and nutrients throughout the plant’s body; majority of plants; evolved from algae-like ancestors
Epidermis –one layer of dismal tissue (first year of growth)
Periderm –replaces epidermis of stems and roots for plants that live more than one growing season
Trichome –hair like extensions, dermal cells that modify
Cuticle –layer of wax and fatty acids (cutin) found outside the cell wall helps to limit water loss
Epidermis –one layer of dismal tissue (first year of growth)
Periderm –replaces epidermis of stems and roots for plants that live more than one growing season
Trichome –hair like extensions, dermal cells that modify
Cuticle –layer of wax and fatty acids (cutin) found outside the cell wall helps to limit water loss
Vascular tissue system –continuous system of tissues that conduct water minerals and food
Xylem –brings water and nutrients from the roots to the other parts
Phloem –moves sugars and other organic nutrients from leaves to the other parts
Sap –contents transported by xylem and phloem
Tracheids –long cells with tapered ends; first water conducting cells to evolve in vascular plants align with each other to form continuous water conducting system
Pits –thin regions n primary walls of tracheids; aligns with pits of adjacent tracheids
Vessel elements –water conducting cells that transport water and minerals more rapidly; dead at maturity
Sieve Tube Members /Elements –alive and active at maturity; brings organic nutrients from the leaves to other parts; believed to be arising from the meristem others think they are highly defirrentiated form of parenchyma
Sap –contents transported by xylem and phloem
Vessel elements –water conducting cells that transport water and minerals more rapidly; dead at maturity
Sieve Tube Members /Elements –alive and active at maturity; brings organic nutrients from the leaves to other parts; believed to be arising from the meristem others think they are highly defirrentiated form of parenchyma
Sieve plates-cell walls with membrane-lined pores that allow materials from cell to cell
Companion cell –cell that shares its nucleus to the siee tube members which do not have nucleus at maturity
Callose –carbohydrate molecule formed by sieve tube members when damaged; around the components of cell wall in its sieve plates
Sieve cell –primitive type of water conducting cell in non-flowering plants
In most dicots:
Cortex- region between the vascular bundles and the epidermis
Pith – center of the stem; inside the ring of vascular bundle