ROOTS Flashcards
Are cylindrical structures which are usually located beneath the surface of the soil through which materials move from the soil
to various part of the plant
Roots
What are the types of roots based on origin?
Primary root, secondary roots, tertiary roots, adventitious roots
Two types of roots system
Fibrous or diffuse system, tap root system
Root anatomy
Regions of the root from the tip to the root hair zone, cross sectional region
Functions of the roots
Support, food storage, photosynthesis, protection, nitrogen fixation, aeration
The first root formed which is
the extension of the embryonic
root or radicle which is the
growing tip of the hypocotyl
Primary root
Roots arising from the primary root
Secondary roots
Roots arising from the secondary roots whose branches are called rootlets
Tertiary roots
Roots which arise from the plant structures other than roots
Adventitious roots
Two types of adventitious roots
Brace root, prop root
Roots which arise from the main trunk stem
Brace root
Roots which arise from the lateral branches of the main stem
Prop root
Scientific name of corn
Zea mays
Consists of several main roots that branch to form a dense mass of intermeshed lateral roots
Fibrous or diffuse root system
Consists of one main stem which arises lateral roots
Tap root system
A thimble-shaped region that protects the growing tip of the root
Root cap region
Contains the apical meristem where the cells are actively dividing and where the primary meristems are formed
Meristematic or Embryonic region
What are the primary meristems that are formed in the apical meristem?
Procambium, ground meristem, protoderm
Two parts of root cap
Peripheral, columella
Cells increase in length which results in the growth or increase in the length of the roots
Region of elongation / region of cell enlargement
In this region, cells have already attained their final structural characteristics
Region of maturation / Region of cell differentiation
In dicots, region of maturation or region of cell differentiation is subdivided into:
Root-hair zone, zone of primary permanent tissue, zone of secondary tissues
In monocots, region of maturation or region of cell differentiation is subdivided into:
Root-hair zone, zone of primary permanent tissue
There are no secondary tissues
present because monocots,
generally, do not have cambia
where secondary tissues are
derived.
It is usually a single layer of
cells derived from the protoderm which covers and protects the inner root
Epidermis or outer region / dermal region
It is the region derived from the ground meristem
Cortex or middle region
Cortex or middle region is composed of:
Outer collenchyma, middle parenchyma, inner endodermis
This types of cross sectional region consists of pericycle, primary xylem, primary phloem, vascular cambium
Stele or vascular cylinder
One of the functions of the roots which involved pneumatophores
Aeration
Scientific name of mangrove
Rhizophora spp
The formation of root nodules containing bacteria in their cells
Nitrogen fixation
Scientific name of Peanut
Arachis hypogaea
Presence of spines
Protection
What is the scientific name of a round-leaf orchid?
Amerorchis rotundifolia
Example of plants which has brace roots
Rubber tree, five fingers
Example of plants which has prop roots
Corn, pandan
Example of plants which has clinging roots
Creeping ivy
Example of plants which specialized food storage
Radish, sweet potato, turnips, carrots
It is where all the cells are derives from the apical
meristem
Zone of primary permanent tissue
It is where tissues derives from the cambia either replace or are added to the primary tissue
Zone of secondary tissues
Characteristics of tap root system
- Consists of one main stem which arises lateral roots
- derived from radicle
(embryonic root) - Anchorage
- In dicot and gymnosperm
- Secondary growth
- Fleshy taproot –carrots,
beets, radish - Lateral roots ( swollen) –
sweet potato, cassava
Characteristics of fibrous or diffuse root system
- Consists of several main roots that branch to form a
dense mass of intermeshed lateral roots - Produced After the death of radicle
- Source: Root primordia (at base of
radicle) - Delicate and hair-like
- Absorption
- No prominent enlarged primary
root - In monocot
It catalyzes the growth of the plant
Growth regulator / Plant hormones
Types of plant hormones
Auxin, gibberellins (gibberellic acid), abscisic acid (dormin), ethylene, cytokinin (kinetin)
Development of root without prior fertilization
Parthenocarpy
Difference between dicot and monocot
Dicot; has cambia, monocot; has no cambia
