plant structure and growth Flashcards
(37 cards)
developmental plasticity
the ability to alter form in response to its environment
plant organs
roots- rely on sugar produced by photosynthesis
stems
leaves
(shoots) reply on water and minerals absorbed by the root system
roots
anchor the plant
absorbing minerals and water
storing organic nutrients
taproot
one main vertical root that gives rise to lateral roots
adventitious roots
arise from stems or leaves
fibrous root
monocots, no main root
root hairs
absorbtion of water and minerals occurs
vast number incereases surface area
stem
organ consisting of:
alternating nodes- point of which leaves are attached
internodes: the stem segments between nodes
axillary bud
potential to form a lateral shoot or branch
apical bud
located near shoot tip and causes elongation of young shoot
apical dominance
helps maintain dormancy in most nonapical buds
rhizomes
horizontal shoot grows just below surface
bulbs
verticle underground shoots consisting of enlarged bases of leaves that store food
stolons
horizontal shoots grow along surface; allow asexual reproduction
tubers
enlarged ends of rhizomes or stolons, food storage
leaf
main photosynthetic organ
flattened blade and stalk called petiole which joins blade to node and stem
tissue
dermal-skin
vascular - fluid movement
ground- other function including photosynthesis storage an support
vascular tissue system
carries out long distance transport of materials between roots and shoots
xylem( water and minerals) and phloem (organic nutrients to roots)
water conducting cells of xylem
trachieds - align end to end to form long micropipes
vessel elements
dead at maturity
sieve plates
porous end walls that allow fluid to flow between cells along the sieve tube
each sieve tube element has a companion cell whose nucleus and ribosomes serve both cells
parenchyma cells
thin and flexible walls
least specialized
perform metabolic functions
collenchyma cells
grouped in strands and help support young part of the shoot
thicker and uneven cell walls
often mechanical support for young and growing parts
sclerenchyma cells
highly specialized for mechanical rigidity
thick secondary walls
often dead at maturity- xylem cells
meristems
embryonic tissue and allow for indeterminate growth