3.1: Plant Tissues Flashcards
- derived from apical meristems
- composed of primary tissues
- constitues the herbaceous parts of the plant
primary plant body
- derived from lateral meristems
- composed of secondary tissues
- constitutes wood/bark of a plant
secondary plant body
most common type of plant cell:
- thin, flexible primary walls
- constitutes as herbaceous parts of plants
- fills up empty space in plants
- totipotent
parenchyma
parenchyma found in stem; bring structure
pith parenchyma
Composed of tightly packed parenchyma cells
pith tissue
parenchyma found in roots; sink organ
cortical parenchyma
parenchyma found in seeds
storage parenchyma
parenchyma found in leaves; mainly for photosynthesis
chlorenchyma
“air infusion” network formed from individual parenchyma cells; for respiration (mostly aquatic)
aerenchyma
single layer of parenchyma cells that serves as the outermost layer
epidermis
type of epidermis: contain hydrophobic compounds that cover epidermis
- major novelty in the evolution of land plants to colonize the land
cuticular membrane
functions of cuticular membranes
- prevents dessication
- inhibit pathogen invasion
- blocks certain wavelengths of UV radiation
type of epidermis: top translucent layer tightly packed to avoid loss of water (undifferentiated)
pavement cells
type of epidermis: protection of mesophyll, subjacent to epidermis (usually bigger, not always present)
hypodermis
what does the hypodermis do?
it heightens absorption of light in lower layers where little amount of light is reached
part of epidermis: regulates entry of CO2/ exit of water, O2
prevents water loss
stomatal pore complex
specialized epidermal cells: change shape when swollen with water; can photosynthesize
guard cells
specialized epidermal cells: work w guard cells, normally supply potassium
subsidiary cells
distribution of stomatal pore complex: adaxial (top of leaf)
epistomatic
distribution of stomatal pore complex: abaxial (under leaf)
hypostomatic
distribution of stomatal pore complex: both adaxial and abaxial
amphistomatic
extensions of epidermis that protect leaves from biotic/abiotic stresses
trichomes
functions of trichomes
- raises humidity in air directly in contact w leaf surface
- reduce amount of light entering lead mesophyll
- protect from herbivory w physical/chemical barrier
- avoid water loss/ excess evapotranspiration
trichome shape: tip breaks=chemical components injected
stinging hair
plant family with release chemical like a needle in trichome
urticeae
trichome shape: biosynthesis of secondary metabolites occuring in secretory disk cells lining base of globular trichome head (repels insects)
glandular trichome
type of plant cell: structural tissue to support function w/o restraining growth; in young parts of plant; alive and exhibits plasticity
collenchyma
type of collenchyma: forms angles between cells; for circular cells and wall thickening
angular collenchyma
type of collenchyma: unidirectional filling between rectangular cells
lamellar collenchyma
type of collenchyma: intracellular space in center of “angles”; in plants that need inc gas exchange in tissue while being strong
lacunar collenchyma
type of collenchyma: evenly deposited primary wall thickenings; little/no intracellular spaces
annular collenchyma
fatty substance that makes the wall impermeable to water; forms cuticle layer
cutin
thinner region where only primary wall is present; interrupts secondary walls of tracheids & vessel elements
pits
type of cell: supports plant by strength alone; stronger than collenchyma; provide long-distance water transport; dead cells
sclerenchyma
type of sclerenchyma: provide most leaf support; protects phloem; elongated w tapered ends; found in cortex clusters
fibers
type of sclerenchyma: compact singly or in clumps; strongly related to hormonal signals
sclereids
kind of sclereid: (in fruits) give strength/support to peduncle of fruits; smallest kind
brachysclereids
forms leaf scars for wounded plant to protect/strengthen area
sclerification
kind of sclereid: (in leaves) strengthened by lignin + calcium oxalate crystals; helps form shape
astrosclereids
kind of sclereid: (in seeds) protects seeds by forming seed coat in legumes
macrosclereids, osteosclereids
functions of macrosclereids, osteosclereids
- deter herbivory/ insect attacks
- prevent water loss/ dessication
- prevent dormancy-promoting hormones from leaching out
kind of sclerenchyma: helps w movement of water from roots to leaves during transpiration; conducting cells of xylem
tracheary elements
type of tracheary elements: long narrow vessel elements w tapered ends
tracheids
type of tracheary elements: short wide w various end-wall styles;
aligned end to end forming long pipes called vessels
vessel elements
exhibits determinate growth; stop growing after reaching a certain size
animal growth
exhibits indeterminate growth; growth occurs throughout plant’s life
plant growth
group of cells capable of dividing indefinitely; production of new growth
meristems
type of meristem: for primary growth/ length
apical meristems
two types of apical meristems
root apical meristem (RAM), shoot apical meristem (SAM)
type of meristem: for secondary growth/thickness
lateral meristems
type of lateral meristem: gives rise to secondary xylem where most thickening takes place
vascular cambium
type of lateral meristem: replaces epidermis w tougher periderm
cork cambium
made possible by apical meristems at the tips of shoots and roots
primary growth
made possible by two lateral meristems extending along the length of a shoot or root where primary growth has ceased
secondary growth
type of primary tissue: outermost region that will give rise to epidermis
protoderm
type of primary tissue: consists of parenchyma cells that will give rise to ground tissues
ground meristem
in ground meristem: protect/maintain vascular bundles; interior to epidermis; homogenous photosynthetic parenchyma+collenchyma
cortex
type of primary tissue: provides primary tissues to vascular system
procambium
from procambium: conducts water and minerals; dead but functional at maturity
xylem
from procambium: distributes sugars and minerals; alive at functional maturity
phloem
2 types of conducting cells in xylem (tracheary elements)
tracheids
vessel elements
a set of rings secondary walls are organized in
annular thickenings
2 types of conducting cells in phloem (sieve elements)
sieve cells
sieve tube members
immature parenchymous sieve elements enlarge plasmodesmata’s diameter forming…
sieve pores
sieve pores occuring as clusters; regulates flow of water
sieve areas
tracheary element: long, thin cells w tapered ends; water move from cell to cell mainly through pits
tracheids
tracheary element: wider, shorter, thinner walled, less tapered than tracheids;
aligned end to end forming long pipes known as vessels
vessel elements
sieve element: elongated spindle shaped; sieve areas are distributed over all its surface; found only in non-angiosperms
sieve cells
sieve element: have large sieve pores, sieve areas are rather small; stacked end to end w their large sieve area aligned called sieve plate; only in angiosperms
sieve tube members
from procambium: contain both xylem+phloem strands running parallel to each other;
interior to cortex
vascular bundle
arrangement of vascular bundle: more defined, scattered in…
monocots
arrangement of vascular bundles: forms ring surrounding pith in…
dicots
