ACTIVITY 6 Flashcards
part of the ___ of (vascular or nonvascular?) plants that typically appear ABOVE the ground
- sporophyte
- vascular plants
SHOOT SYSTEM
the shoot system is made of (branched or unbranched?) _____ stem axis
with 4 appendages, namely?
- either branch or unbranched
- aerial
- leaves
- buds
- flowers
- fruits
2 functions of stem
- support of aerial parts
- transport of materials between roots and leaves
the stem is a/an ______ system of _____ and _____
- alternating
- nodes (point where leaves and branches grow) & internodes (segment between 2 nodes)
what can be found at the apex (highest point) of the stem?
+ its function
apical meristem - responsible for increase in plant height
shape of SHOOT APEX of stem + what type of cell constitutes this?
- dome-shaped
- meristematic cells
the apical meristem gives rise to??
+ each differentiates into what?
+ function
the primary meristems
- protoderm - epidermis (outermost)
- ground meristem - cortex and pith (next to protoderm + middle)
- procambium-vascular tissues (between ground meristem)
responsible for primary growth of primary tissue
2 buds located in the stem + specific location + function
- Terminal Bud = extreme tips of the main stem and branches (for vertical growth)
- Axillary Bud = angles between leaves and internodes (for growth of branches and flowers)
LEAF SHEATH
- definition
- location
- function (2)
- a cylindrical structure that surrounds the base of a leaf
- connects leaf to nodes
- protects the young shoots and supports the plant
INTERCALARY MERISTEM
- composition
- location
- function
- composed of actively dividing cells
- located between mature tissues (@ base of leaves and internodes)
- enable growth in length
EXTERNAL MORPHOLOGY OF WOODY STEM
3 PARTS
- function
- location
- age of stem
- stomata
- gas exchange
- epidermis
- young woody stems - lenticels
- gas exchange
- beneath stomata
- old woody stems - leaf scar
- mark formed upon detachment of leaf
- typically below a bud
STELE IN:
- dicot
- monocot
DICOT: eustele
MONOCOT: atactostele
8 MODIFIED STEMS
- Bulb - fleshy storage leaves (onion)
- Corm - globous with few scale like leaves (gabi)
- Rhizome - horizontal underground with short internodes and scale like leaves (ginger)
- Tuber - underground storage stem with buds (no storage leaves or scales like POTATO)
- Runner - horizontal aboveground stem with long internodes
- Cladophyll - look like leaves
- Stem Tendril - coiling branch
- Thorn - sharp pointed stem
plant growth is generally described as ____ or ____ + reason
- open or intermediate
- plants can continue growing and adding new organs throughout their lifespan due to meristems.
WHAT meristematic tissue is involved in INCREASE IN DIAMETER of plant body
+ 2 types
+ these produces _____
+ which TYPES can be seen in dicot and monocot?
LATERAL (or secondary) meristems
- vascular cambium
- cork cambium
- secondary tissues
dicot: usually both (but some dont have number 1)
monocot: usually cork cambium only (but some have both)
due to monocots USUALLY having only the CORK CAMBIUM as ____ (what type of meristematic tissue?), they demonstrate ______ _____ _____
- lateral meristems
- anomalous secondary growth*
*which can be exhibited by some dicots
WHAT specific type of plants DEMONSTRATE anomalous secondary growth
*CLUE: the answer is NOT monocot or dicot
woody plants - exhibits secondary growth
herbaceous plants: don’t
2 type of xylem
- Protoxylem (smaller: first to mature)
- Metaxylem (larger: matures afterward)
2 types of XYLEM MATURATION
- EXARCH (protoxylem closer to cortext)
- ENDARCH (protoxylem closer to center)
DICOT vs MONOCOT stem internal structure
+ difference in parts
DICOT: organized vascular bundles (has PITH)
MONOCOT: random positions of vascular bundles (NO pith)
SHOOT APEX important parts (4)
+ identify their location in photograph
- primary meristems
- tunica
- corpus
- leaf primordia
DICOT STEM xylem maturation?
endarch
MONOCOT STEM xylem maturation?
endarch
What happens to the primary xylem and primary phloem eventually as the lateral meristems continue producing secondary tissues?
PRIMARY XYLEM
- remains intact inside stem core but gets compressed inward = becomes non-functional
PRIMARY PHLOEM
- gets crushed and displaced outward = becomes non-functional
Where can you find the newly formed layers of secondary xylem and secondary phloem?
NEWLY FORMED XYLEM
- inside vascular cambium (pushes older xylem inward)
NEWLY FORMED PHLOEM
- in the bark, outside vascular cambium (pushes older phloem outward)
What tissues can be found in the ff:
- Bark (3)
- Wood (2)
- The BARK includes all tissues external to the vascular cambium, which are:
- Periderm
- Secondary phloem
- Remaining primary phloem
- The WOOD includes all tissues internal to the vascular cambium, which are:
- Secondary xylem
- Primary xylem
What is the main component of wood?
Secondary xylem
SAPWOOD vs HEARTOOD composition
+ location
SAPWOOD - newer secondary xylem (outer wood)
HEARTWOOD - older primary xylem (inner wood)
