ACTIVITY 5 Flashcards
what is the ROOT SYSTEM?
underground portion of the sporophyte of vascular plants
3 functions of the root system
- absorption of water and minerals
- anchorage
- production of certain hormones.
EMBRYO of the seed plant that gives rise to primary root
radicle
3 TYPES OF ROOTS
- Primary Roots (first formed roots)
- Lateral Roots (roots originating from pre-existing roots)
- Adventitious Roots (from other organs other than roots)
What do ROOTS not posses (2)?
Nodes and Internodes
What type of plants have roots and what does not?
VASCULAR PLANTS: have
NONVASCULAR PLANTS: don’t (they have rhizoids instead)
2 functions of rhizoids in NONVASCULAR PLANTS
anchorage and absorption
What do you call the appendages present in roots?
+ its main definition
+ present in what type of roots?
+ origin
+ main function (1)
+ what type of roots has the same function?
ROOT HAIRS
- hair-like appendages
- found in young roots
- from specialized epidermal cells (TRICHOBLASTS)
- increase area for absorption of water and minerals
LATERAL ROOTS
ALL ______ tissues of _____ are derived from its ______
PRIMARY
ROOTS
APICAL MERISTEM
MODIFIED ROOTS
- became specialized due to?
- developed ____ characteristics
- evolution
- distinctive
6PARTS of a dicot root
- Cortex
- Endodermis
- Xylem
- Phloem
- Epidermis
PARTS of a monocot root
- Cortex
- Endodermis
- Xylem
- Phloem
- Epidermis
- Pith
7 modified roots
- storage roots (starch)
- aerial roots (adventitious roots that dont reach the soil)
- prop roots (adventitious roots that reach the soil + support)
- contractile roots (contract vertically + pulls the rootstock further into the soil)
- Haustoria (roots of parasitic plants)
- Pneumatophores (grow upward for gas exchange)
- Buttress roots (large, horizontal, vertically thickened @ base of trees)
Example of pneumatophores
mangrove trees
Part of root with active cell division
+ WHAT do you call this as a whole
root cap
region of cell elongation
3 primary meristems at root cap?
- protoderm (outermost, forms epidermis)
- group meristem (in between, forms cortex)
- procambium (innermost, forms stele: vascular tissues/vessels)
Part of root that are epidermal outgrowths?
+ WHAT do you call this as a whole
root hairs
region of cell maturation
Root epidermis has how many layer of cells?
thus, what are they called (2 terms)?
+ what are exceptions to this?
1 layer
simple epidermis OR uniseriate
- aerial roots of orchids: multiseriate/multiple epidermis
What is STELE in monocot roots?
Inner portion of endodermis that is the CENTRAL CYLINDER OF VASCULAR TISSUES
Is zea mays dicot or monocot?
monocot
ENDODERMIS
- ____ barrier
- function
- cells in this layer are covered with a strip called _____ made of (2) for waterproofness
- selective barrier
- regulates passage of substances from substance to vascular tissues
- CASPARIAN STRIP - lignin and suberin
where do LATERAL ROOTS come from?
- in vascular plants w seeds?
- in seedless vascular plants?
w seeds: PERICYCLE (outermost layer of stele)
w/o seeds: ENDODERMIS
2 type of xylem in DICOT ROOTS + definition
- Protoxylem (smaller: first to mature)
- Metaxylem (larger: matures afterward)
2 types of XYLEM MATURATION in DICOT ROOTS
- EXARCH (protoxylem closer to cortext)
- ENDARCH (protoxylem closer to center)
Typical arrangement of xylem in phloem in dicot roots
Radial Vascular Tissue (alternation phloem and xylem: cross-like shape si xylem)
Type of stele TYPICAL to DICOT roots
Type of stele TYPICAL to MONOCOT roots
DICOT: protostele (no pith, phloem surround xylem)
MONOCOT: siphonostele (w pith)
