plant structure & growth Flashcards
what are plant structures composed of?
organs, tissues, cells
what are the plant organs?
roots: root system
stems: shoot system
leaves: shoot system
what do roots do for the plants?
-anchor plant and absorb nutrients
-store carbs and other reserves
-primary roots are 1st to emerge from germinated seed & branches to form lateral roots
what type of roots are there?
taproots, fibrous roots, root hairs
what are taproots?
-tall erect plants with large shoot masses
-absorption restricted to large lateral roots
-favorable for light, pollen, seed dispersal, and specialized food storage
what are fibrous roots?
-small plants for those with trailing growth habits
-more efficient anchoring for grazing animals
-primary roots dies early and does not form taproot (roots emerge from stem)
what are root hairs?
-thin extensions of root epidermal cells
-increase SA of root
-form symbiotic interactions with soil fungi, where absorption takes place
what types of roots form from evolutionary adaptations?
1) prop roots
2) storage roots
3) pneumatophores
4) buttress
5) strangling aerial roots
prop roots
support tall, heavy top plants
pneumatophores
obtain oxygen during low tide
buttress roots
supports trunk of trees in moist, tropic conditions (shallow systems)
strangling aerial roots
wraps host tree to take its nutrients
what are the stem characteristics?
-elongate over time
-orients shoot to maximize photosynthesis
-bears leaves
-elevates reproduction structures
what are the 4 stem structures?
1) nodes
2) internodes
3) apical bud
4) axillary bud
nodes are…
internodes are…
points where leaves attach
stem segment b/w nodes
apical bud…
axillary bud…
growing shoot tip with apical meristems
forms lateral branch, thorn, or flower b/w pedial and stem
what are some adaptations in stems?
tubers: food storage
stolons: horizontal shoots along ground, asexual reproduction
what are some characteristics of leaves?
-main photosynth organ of vascular plants
-gas exchange
-dissipates heat and defends plant
what is the blade, pedial, and veins?
blade: flattened portion of leaf
pedial: stalk that joins leaf at stem of node
veins: vascular tissues of leaves
characteristics of angiosperm leaves
-simple leaves
-compound leaves: can withstand strong winds/pathogens, consists of multiple leaflets
what are the adaptations of leaves?
tendrils: helps lasso/coil to another plant
spines: protective functions
reproductive: produce plants from leaves that fall and take root
storage: short underground stem that holds food
what is dermal tissue?
-plants outer protective covering
-in woody plants the protective tissues replace epidermis in older regions of periderm during secondary growth
what is ground tissue?
-pith is internal to vascular tissue
-stores carbs, short distance transport, photosynthesis
-cortex surrounds vascular tissue
what is vascular tissue?
-facilitates transfer of materials
-provides mechanical support
-xylem and stele (vascular tissue of root/stem)
