Roots Flashcards
similarly sized roots; arise when radicle dies during or immediately after germination
Fibrous Root
Enumerate 3 functions of Root System
- Anchorage
- Absorption of water and minerals
- Production of hormones
(cytokinin and gibberrelin)
Hypocotyl:
Cotyledons, Root hairs, radicle
zone of root cap which detects gravity and contains starch
columella
arise from epidermis; single celled; increases absorptive area
Root hairs
2 zones of root cap
Peripheral
columella
arise from main stem or trunk
Brace root
smaller and arise from tap root; multicellular; responsible for second growth for dicot
Lateral or branch roots
increases the absorptive and transport capacity of the roots.
Adventitious
the growing portion in length occur, which is protected by the root cap.
root tip
3 fnx of root cap
- Protects the root apical
- Produces mucigel
- for positive geotrophism
lubricates the passage of root through the soil
mucigel
contractile roots of bulbs like onions, gladiolus, garlic
Movement
Enumerate the 3 types of Root System
- Tap root
- Fibrous root
- Adventitious
arise from lateral branches
. Prop root
zone of root cap which protect and is composed of dead cells
Peripheral
diffusion through intercellular spaces
Apoplastic
mitotically inactive region of the root apical meristem; act as reserve of healthy cells ; resistant to toxic substances and radiations.
Quiescent center
causes the soil to release nutrient ions and permits diffusion to the roots
Root cap
zone where Root hairs grows outward and the most significant activity is the
transfer of mineral from the
epidermis to the vascular
bundle
Zone of maturation
modified roots that provide support
Brace, Prop, Clinging, Buttress
specialized roots that is for water retention
Velamen in aeria roots of orchids
Stele or Vascular Cylinder: consists of: (4)
Pericycle
Primary phloem
vascular cambium
primary xylem
site of lateral root growth
Pericycle
layer before the stele of the root
controls the passage of minerals accross V. tissues
Endodermis
Type of Stele
Protostele - dicot (w/o pith)
Siphonostele - monocot (w/ pith)
Endodermis consists of:
- thick walled cells (suberin and lignin)
2. Passage cells
zone in root tip where cells begin to differentiate into visible pattern and where there is no cell maturation happening
Zone of elongation
after ___ tap root becomes the largest root in the system
germination
shows outer zone of collenchyma middle zone of parenchyma and innermost endodermis
CORTEX
Type of stele which is a band of vascular tissues surroundinig a parenchymatous pith
Siphonostele
modified roots that is for aeration
Pneumatophores
diffusion through plasma membrane and enters the protoplasm (osmosis)
Symplastic
where does tap root develop in the embryonic root ?
radicle
Zone which is protected by thick layer of cell
Rapidly dividing cell
Zone of Cell Division
Pith is present
Monocot
it destroys the cells of the cortex and epidermis that lie in its path
lateral root
Specialized roots for absorption
Parasitic (haustorial roots)
modified roots that is photosynthetic
Green aerial root
modified roots that provide food storage
Enlarged, fleshy, succulent root
Largest region is cortex (monocot or dicot)
MOnocot
Specialized roots for photosynthesis
Chlorophyllous roots
association between a soil fungus and roots
Mycorrhizae
expanded roots for great support, upper side grows faster than the lower side.
Buttress
examples of Enlarged fleshy tap root
carrots, ube, tugue, radish, turnips
