Unit 3: Roots (B) Flashcards
parts of the root
root hair
root cap
root tip
meristematic region
region of elongation
region of differentiation
xylem
phloem
stele
pericycle
cortex
- a hair-forming cell on the epidermis of a plant root
- found only in the region of maturation of the root
root hair
protects the roots from mechanical abration
root cap
- aka as apical meristem
- contains ______ which functions for protection
ROOT TIP
mucigel
region where there is high reproduction of cells or mitosis occurs
meristematic region
region where cells grow “longer”
region of elongation
region where cells have their specific functions and continue to grow
region of differentiation
contains xylem vessels, large cells and tubes for conducting water upwards
xylem
contains sieve tube members and companion cells for conducting food upwards and downwards
phloem
the central part of the root or stem containing the vascular tissues and pith
stele
region where branch and lateral roots grow
pericycle
made of parenchyma
cortex
- inner layer of the cortex that contain ___________ which prevents water from passing between endodermal cells to enable the endodermis to regulate the uptake of water and minerals into the xylem.
ENDODERMIS
casparian strips
the outermost layer of cells of the root that protects the inner tissues
epidermis
Function of Roots
- Anchorage
Two Mechanisms or Pathways:
a. __________: set of interconnected porous cell walls which function for conduction of water
b. __________: involves an interconnected cytoplasm for the conduction of water and minerals - Absorption of oxygen, water and dissolved nutrients from the soil
- Storage
- Roots also provide home or host sites for bacteria and fungi which can assist in the breakdown and assimilation of nutrients from the soil.
For example, nitrogen fixing bacteria which are found in the root nodules of most legumes.
- Helps in asexual reproduction especially during unfavourable conditions.
- anchorage
a. Apoplastic pathway
b. Symplastic pathway
SPECIALIZED ROOTS
- Aerating roots
- Aerial roots
- Contractile roots
- Haustorial roots
- Nodule
- Mycorrhyza
- Propagative or reporoductive roots
- Prop roots
- Storage or fleshy roots
- or knee root or knee or pneumatophores or Cypress knee
- roots rising above the ground, especially above water such as in some mangrove genera
aerating roots
- roots entirely above the ground and can be classified as climbing, photosynthetic, velamen and floating
aerial roots
- they pull bulbs or corms of monocots, such as hyacinth and lily, and some taproots, such as dandelion, deeper in
the soil through expanding radially and contracting longitudinally. - have a wrinkled surface.
contractile roots
roots of parasitic plants that can absorb water and nutrients from another plant, such as in mistletoe and dodder
haustorial roots
- A small knoblike outgrowth, as those found on the roots of many leguminous plants
- contain nitrogen-fixing bacteria that converts nitrogen (N2) to nitrate (NO3)
nodule
- known from 90 percent of plant species and are a mutualistic association of a fungus with plant root tissue
mycorrhyza
roots that form adventitious buds that develop into aboveground shoots, termed suckers, which form new plants, as in lilies, garlic, cherry and many others.
Propagative or reproductive roots
roots that has strong anchorage like corn
prop roots
roots are modified for storage of food (starch or sucrose) or water, such as carrots and beets
storage or fleshy roots
