Roots Flashcards
4 major plant parts
leaf flower stem roots
types of roots
fibrous, taproot, storage root, prop
function of roots
Anchor plant in soil
uptake water
uptake dissolved nutrients
store food reserves
primary roots
comes from radicle of the embryo and gives rise to the taproot
secondary roots
roots that grow from the primary root
fibrous roots
no visible primary root
clumps of very thin roots
usually in shallow soil. it knits up the soil.
ex. grass.
tap roots
large descending primary root, many secondary roots branching from primary root, typically grow in very deep soil. lots of space for storage
ex. carrot
storage roots
large primary root structure stores food reserves, found on biannual and perennial plants, regenerate vegetative growth after winter, agricultural root crops.
ex. beets
apical meristem
growth at region of the tip of the roots
root cap
cell mass protecting meristem
epidermal cells
outer skin of root
root hairs
responsible for uptake of water and dissolved nutrients
vascular tissue
xylem and phloem; the “plumbing” of the plant
cambium
meristematic; growth in girth
cortex
internal root tissues for storage
endodermis
inner most layer of cortex
pericycle
layer of cells that surrounds vascular tissue
perenchyma
simple permanent tissue in the plants. thin walled and makes up the bulk of the plants soft tissues
active transport
uses ATP
passive transport
uses no ATP
diffusion
can be anything-
movement of particles from areas of higher concentration of areas of lower concentration until equilibrium.
osmosis
is diffusion of water through a semipermeable membrane separating 2 solutions
how to plant roots absorb water
water uptake through osmosis
hypertonic
lower H2O concentration outside of cell
H2O moves out
cell shrinks
isotonic
Equal H2O concentration in and outside of cell
hypotonic
Higher H2O concentration outside of cell
H2O moves inn
cell expands
where does osmosis happen
root hairs.
Fluid transfer
When water and nutrients are drawn up the soil
causes imbalance between cell content and soil
They pass through cell membrane in root hairs to balance deficiency
Turgor
internal water pressure of plant
(crunchiness of lettuce/ erect penis is erect because of blood flow causing turgidity)
Underwatering
Plant will wilt. not enough water means plant will deflate. water loss will happen from the roots causing plant to wilt and shut down the physiological process
Overwatering
Soil cant distribute too much water to plants unless it is saturated. The plant wont absorb any more water if turgid. Soil is saturated with water and the root hairs die from lack of oxygen. End the uptake of water and nutrients. - overwatering = turgidity + no oxygen in soil = death
