ch. 35 Flashcards
cell
fundamental unit of life
tissue
group of cells working toward common functions
organ
several types of tissues that together carry out particular functions
different plant organs
roots and shoots
different organ systems of plant
root and shoot systems
purpose of roots
- anchors plant
- absorbs minerals and water
- stores carbohydrates
what is the first root to emerge?
primary root
what does the primary root branch to form
secondary and tertiary roots
what do secondary and tertiary roots do
improve anchorage and water absorption
what root system do tall plants with large shoot masses generally have
taproot system
taproot
develops from primary root and anchors plant to soil
where on the roots does absorption primarily occur?
tips of tertiary roots
small or trailing plants generally have what type of root system
fibrous root system
fibrous root system
spreads out like thick mat below soil surface
- primary root dies early on and doesn’t form taproot
adventitious roots
arise from stem and give rise to many branching lateral roots
root hairs
finger-like extensions of epidermal cells that form near the root tip and increase the absorptive surface of the root
what do most root systems form?
mycorrhizal associations
different types of specialized roots
buttress, “strangling” aerial”, pneumatophores, storage, prop
pneumo
lung or breath
phore
to bear
what does a stem consist of
- alternating system of nodes
- internodes
nodes
points at which leaves are attached
internodes
stem segments between nodes
what causes elongation of a young shoot
apical meristem of the apical bud
axillary bud
structure that has the potential to form a lateral branch, thorn, or flower
meristematic tissues within the axial buds does what?
remains dormant
- hormonally depressed from above
apical
at the tip or top
axill
arm pit
apical dominance
terminal bud released auxin, inhibiting growth of lateral buds
pruning (apical bud decapitation)
removing terminal bud allows dormant lateral buds to develop, producing bushier plants
primary function of stem
to elongate and orient shoot to maximize photosynthesis
ex. of modified stems
rhizomes, stolons, tubers
bulbs
structurally short stems with fleshy leaves or leaf bases
corms
rounded, underground storage organs consisting of a swollen stem base covered with scale leaves
leaf
main photosynthetic organ of most vascular plants