nodes
areas of a stem where one or more leaves attach
Nodes and internodes are a(n) ____________, NOT a(n) ________________
area, structure
lateral bud/axillary bud
dormant apical meristem has potential to form a new branch (shoot)
3 things that differentiate stems from roots
photosynthesis capabilities ability to form leaves no gaps in vascular cylinders in roots
internode
area of stem between nodes
function of the stem
support of leaves transpiration/conduction of water, minerals, nutrients production of new shoot tissue photosynthesis
similarities between shoot tip and root tip
grows at tips houses apical meristem
differences between shoot tip and root tip
stems produce leaves and lateral branches from shoot apical meristem no root cap - is protected by leaf primordia and bud scales
apical meristem makes...
leaf and bud primordia the three primary meristems
leaf primordia
forms new leaves
bud primordia
forms shoots, lateral stems, or flowers
in apical meristem, some cells divide... (two terms)
periclinally, and others anticlinally
periclinal division
division is parallel with apical surface (upwards, adds layers)
anticlinal division
division is perpendicular to the surface (side by side)
the shoot apical meristem has a ___________________ organization (one hyphenated word)
tunica-corpus
tunica
outermost cell layers divides anticlinally
tunica purpose
adds surface to the stem
corpus
innermost cells divide mostly periclinally
corpus purpose
adds bulk, "body" to the stem
primary meristems
give rise to primary tissues of main stem, new leaves, and lateral stems
primary meristem present in...
tunica-corpus organization
protoderm origination in stem
outermost tunica layer (L1)
procambium and ground meristem origination in stem
corpus (L3)
epidermis
1-2 cells thick covers entire stem
epidermis function
houses stomata photosynthesis
cortex
filler tissue in stem
cortex composition in stem
parenchyma collenchyma sclerenchyma
vascular tissue organizations (3)
almost continuous vascular cylinder, narrow interfascicular regions spread out vascular cylinder, wide interfascicular regions scattered vascular bundles
spread out vascular cylinder, wide interfascicular region examples
Tilia (American liden)
almost continuous vascular cylinder, narrow interfascicular region examples
Medicago, Sambucus, Ranuculus (burclover, elderberry, buttercup)
Medicago is pictured.
scattered vascular bundles examples
Zea mays (maize)
interfascicular region
ground tissue in between vascular bundles within the same radius
fascicular cambium
cambium in between the phloem and xylem
Interfascicular region is ____________ vascular bundles, while fascicular cambium is _______________ vascular bundles.
between, within (between xylem and phloem)
"open type" vascular bundles
retain cambium capable of secondary growth
"closed type" vascular bundles
no cambium not capable of secondary growth
transition zone
zone at or near soil level vascular tissue in roots transitions into different stele in their stems
True or false: A few plants do not have a transition zone between their roots and stems.
True
Why do the roots and shoots of the same plant have different patterns of vascular tissue?
Added support Different functions (photosynthesis needs, creation of leaves, branch creation, etc)
leaf trace
one or more vascular bundles cross the cortex and enter the leaf attatched to the node
leaf trace gap
wide spaces above leaf traces, where the diverge toward the leaf
stem modications
stems modified for additional needs
rhizome
a horizontal plant stem with shoots above and roots below serving as a reproductive structure
runner/stolon
horizontal aboveground stems
runner/stolon examples
strawberries Bermuda grass
tuber
specialized storage stem that forms at tips of rhizomes/stolons
corm
underground food storage stems shaped like bulbs
storage stems
aboveground food storage
storage stem examples
kohlrabi
thorns
modded branches from axils of leaves
thorn examples
roses
cladophyll
modded stems that resemble foliage leaves
cladophyll examples
asparagus, prickly pear cactus, butcher's broom
myrmecophytes
makes a symbiotic relationship with ants provides a home to the ants in return, the ants protect the plant