BOTANY LAB: ROOTS Flashcards
Axis of a plant body is composed of two parts
AERIAL PORTION and SUBTERRANEAN PORTION
AXIS OF A PLANT BODY
- Stem
AERIAL PORTION
AXIS OF A PLANT BODY
- Roots
SUBTERRANEAN PORTION
Three types of Appendages arising from the axis
LEAVES, EMERGENCES, HAIRS
THREE TYPES OF APPENDAGES
- Found to be arranged on the stem in a definite manner and bear an intimate structural elation to the skeleton of the axis.
The leaf is the lateral expansion of the stem
LEAVES
THREE TYPES OF APPENDAGES
- Second rank appendages. These are found at the outermost layers of the stem usually present as the cortex and epidermis
EMERGENCES
THREE TYPES OF APPENDAGES
- Third rank of appendages are projections of the outermost layer of the cells
HAIRS
It occurs both on Axis and Leaves, usually without definite arrangement
EMERGENCES and HAIR
The plant body of a vascular plant is composed of three systems of tissues
DERMAL, VASCULAR, FUNDAMENTAL or GROUND SYSTEM
These are distinguished by the relative distribution of the vascular and ground tissues
STEM, ROOT, LEAF
Found between the epidermis and the center of the axis
VASCULAR SYSTEM (stem)
Consists of photosynthetic parenchyma cells known as Mesophyll
GROUND TISSUE
Commonly being arranged in the form of ring bundles as seen in transverse section of stem
PRIMARY VASCULAR
May be absent in monocot roots
PITH
In the root, it generally shed during the secondary
CORTEX
The original primary vascular system may be obscured by secondary vascular tissues between the primary xylem and the primary phloem
SECONDARY GROWTH
Function:
- Anchorage of the plant in the soil
- Absorption of water and minerals
- Conduction of water and minerals upward to the stem
- Reproduction in the form of plant propagation
- Storage of food
ROOTS
TWO MAIN TYPES OF ROOT SYSTEMS
FIBROUS ROOT SYSTEM (monocot plants), TAP ROOT SYSTEM (dicot plants)
TWO MAIN TYPES OF ROOT SYSTEMS
- Grows straight down with a few side branches
TAP ROOT SYSTEM
TWO MAIN TYPES OF ROOT SYSTEMS
- Grows more shallow ‘hairy’; many fine-branching roots
FIBROUS ROOT SYSTEM
4 REGIONS OF TYPICAL ROOT
ROOT CAP, MERISTEMATIC REGION (region of cell division), REGION OF ELONGATION, REGION OF MATURATION
4 REGIONS OF TYPICAL ROOT
- Thimble-shaped cell mass that protects the growing root tip by covering the apex of the root.
ROOT CAP
4 REGIONS OF TYPICAL ROOT
- The location of cell division
MERISTEMATIC REGION (region of cell division)
4 REGIONS OF TYPICAL ROOT
- Area of root lengthening. The cell produced from the meristematic region grow in the elongation region
REGION OF ELONGATION
4 REGIONS OF TYPICAL ROOT
- Where the cells that grew in the elongation region fully develop and become adult cells
REGION OF MATURATION
EXTERNAL STRUCTURE OF ROOT
PRIMARY ROOT, SECONDARY ROOT, TERTIARY ROOT
EXTERNAL STRUCTURE OF ROOT
- First root of a plant, originating in the embryo
PRIMARY ROOT
EXTERNAL STRUCTURE OF ROOT
- Produced on the primary root
SECONDARY ROOT
EXTERNAL STRUCTURE OF ROOT
- Grow in various directions and help in fixing the plant firmly into the soil
TERTIARY ROOTS
INTERNAL STRUCTURE OF ROOT
EPIDERMIS, CORTEX, ENDODERMIS, VASCULAR CYLINDER
INTERNAL STRUCTURE OF ROOT
- The outermost layer that absorbs water and dissolved material from the soil and protects the inner tissue of the root
EPIDERMIS
INTERNAL STRUCTURE OF ROOT
- Found inside the epidermis, which is composed of parenchyma cells with large intercellular spaces, secretory cells, resin ducts, and endodermis
CORTEX
INTERNAL STRUCTURE OF ROOT
- The innermost cell layer that regulates ion movement into the xylem. The Casparian strip embedded in the cell wall inhibits mineral movement through the wall
ENDODERMIS
INTERNAL STRUCTURE OF ROOT
- The innermost layer with the xylem and phloem cells for the conduction of materials, parenchyma cells for food storage and support of the other tissues
VASCULAR CYLINDER
INTERNAL STRUCTURE OF ROOT
Pericycle
- It gives rise to lateral roots, cambium, and the part of the vascular cambium
DICOT
INTERNAL STRUCTURE OF ROOT
Pericycle
- Produces the lateral roots
MONOCOT
INTERNAL STRUCTURE OF ROOT
Xylem & Phloem
- Limited in numbers
DICOT
INTERNAL STRUCTURE OF ROOT
Xylem & Phloem
- Numerous in numbers
MONOCOT
INTERNAL STRUCTURE OF ROOT
Pith
- Absent
DICOT
INTERNAL STRUCTURE OF ROOT
Pith
- Present (large and well developed)
MONOCOT
Occurs in the dicot root while it is absent in monocot root.
SECONDARY GROWTH
TYPES OF MODIFIED ROOTS
ADVENTITIOUS ROOTS, AERIAL ROOTS, PROP ROOTS, PNEUMATOPHORES, PARASITIC ROOTS, STORAGE ROOTS, BUTTRESS ROOTS
TYPES OF MODIFIED ROOTS
- Arise along stem or locations other than base of plant
ADVENTITIOUS ROOTS
TYPES OF MODIFIED ROOTS
- Roots that extend out unto the air, unconnected to the ground
AERIAL ROOTS
TYPES OF MODIFIED ROOTS
- Located on the lower part of the stem of some monocots like corn, grow down into ground, anchor against wind
PROP ROOTS
TYPES OF MODIFIED ROOTS
- Spongy outgrowths from the underwater roots, may extend above water, increase oxygen supply to roots
PNEUMATOPHORES
TYPES OF MODIFIED ROOTS
- Penetrate host plants to parsitize them
PARASITIC ROOTS
TYPES OF MODIFIED ROOTS
- Branch roots of plants like sweet potatoes produce extra parenchyma cells for carbohydrate storage
STORAGE ROOTS
TYPES OF MODIFIED ROOTS
- Produced by certain varieties of fig and tropical trees for support
BUTTRESS ROOT
TYPES OF MODIFIED ROOTS
- Plants that grow in arid regions are known for growing structures used to retain water and used these water supply when the supply in the soil is inadequate
WATER-STORAGE ROOTS
TYPES OF MODIFIED ROOTS
- Produces adventitious buds along the roots that grow near the surface of the ground. The buds develop into aerial stems (suckers). The rooted suckers can be separated from the original root and grow individually.
PROPAGATIVE ROOTS
TYPES OF MODIFIED ROOTS
- Continually pull the plants deeper into the soil as the stem elongates
CONTRACTILE ROOTS
TYPES OF MODIFIED ROOTS
- A mutualistic association with plant roots
MYCORRHIZAE
