Stems Flashcards
Constitutes the ascending axis of the plant
Stem
Give 4 main functions of the Stem
- Provide mechanical support (framework)
Facilitate photosynthesis
Elevate flowers and fruits for pollination and seed dispersal - Provides a pathway for the movement of water and minerals
swollen part where leaves, branches and buds are
attached
Nodes
distance between two successive nodes
Internodes
small, raised dots, ridges for gaseous exchange
lenticels
mark below the axillary bud after a leaf has
fallen
leaf scar
undeveloped shoot
Bud
cut ends of vascular bundle seen within each
leaf scar
Bundle scar
angle between the leaf and the stem
Leaf axil
responsible for Elongation of Internodes
Intercalary
fascicle or also called compressed set of vascular tissues
Vascular bundle
outer collenchyma and parenchyma
Cortex
- open bundle with vascular cambium
2. closed bundle
- Dicot
2. Monocot
extension of pith between 2 vascular bundle
Pith ray
Difference between Intrafascicular and Interfascicular
Intra - cambium within 2 vasc, bundles
Inter cambium between 2 vascular bundle
smaller through time because of secondary xylem
Pith
Bundle sheath cells is for _____
Vascular cambium is for _____
Monocot
Dicot
Big - V
Small - T
Vessel
Tracheid
3 sections in young dicot stem
Dermal
Cortex
Stele
Young dicot stem has
eustele or vascular cylinder
The arrangement of vascular bundles in monocot stem is _____ and is enclosed by _____
scattered or dispersed ; bundle sheath
loose ring of vascular bundles
eustele
- Storage parenchyma
2. Albuminous cells
Ray initials
- Tracheid, vessel elem, fibers
2. SIeve cell, sieve tube members, companion cells, fibers
Fusiform initials
___ system forms ray initials
Radial
___ system forms fusiform initials
Axial
dicot; strengthens and with lots of fibers and vessel elements
Hardwood
dark inner and suberized and lignified wood tha provide support
Heartwood
wood of gymnosperms
Soft wood
lighter that heartwood and is functional
sapwood
is 2* present in modern ferns?
No, it is absent
is 2* present in monocot?
No, it is absent.
Some have anomalous 2* growth
is 2* present in gymno?
YEs
is 2* present in dicot
YEs
annual rings are late ___
Xylem
early wood are ____
Late wood are ____
spring
Summer
Upper side of stem produces many special gelatinous fibers whose walls are rich in cellulose.
Angiosperm: Tension Wood
Underside of the branch produces fibers whose walls are rich in lignin.
Gymnosperm : Compression Wood
Pine stems have ___
resin ducts
advantage of Anomalous Secondary Growht in Potato
speed production of storage capacity
advantage of included Phloem
protection of phloem from insects by one to several layers of wood.
Outermost cells of 2* vasc. bundles develop into ___ with thick secondary walls
Fibes
short stem covered with fleshy blades
for storage and reproduction
give example
Bulb
onion
green stem for photosynthesis, reproduction and storage
ex.
Cladodes - cactus
scaly underground stem for reproduction and storage
ex.
Rhizome - ginger
Swollen outgrowths of stolon for storage and reproduction
ex.
Tubers
solanum tuberosum
for protection in stem of ___
Hooks; rose
horizontal stems w/ adventitous buds; for repro on new plants
ex
Stolons
strawberry
Vertical and short underground stem for repro and storage
ex.
Corm
ex. gabi ot taro
climbing or twining stem support
Twiner
