Leaves Flashcards
The main photosynthetic organ.
leaves
has vascular tissue bundles that arise from the midrib
veins
part of the leaf that is flat and the light-harvesting portion
leaf blade /lamina
Upper leaf zone; VENTRAL; smooth
adaxial surface
Lower leaf zone; DORSAL with large veins portrude
abaxial surface
part of the leaf that that holds the blade out into the light
petiole
Most of this type of plant have parallel major veins of equal diameter that run the length of the blade.
monocot
What is the center main vein of a leaf
midrib
it is the outline of the leaf.
margin
this helps in identification of a species
leaf shape
opposite of the apex and tip of the leaf blade.
base
where does leaves develop?
leaf primordia
function in protecting the bud and photosynthesis
stipule
monocot lack petiole, instead what do they have?
leaf sheath that envelopes the stem
In basal angiosperms and
eudicots what is their venation
netted pattern - reticulate venation
what do you call the venation of monocots with long, strap shaped leaves, the larger veins run side by side with few obvious interconnections
parallel venation
what type of plant where leaf primordia encircle shoot apical meristem.
monocot
Most of these types of plant generally have a branched network of veins arising from the midrib that runs down the center of the blade
dicot
what determines the phyllotaxy?
shoot apical meristem
classifications of leaf margin
entire, toothed, lobed, parted
architectural feature important to light capture.
Phyllotaxy
produced in roots and leaves in response to water deficiency.
Abscisic acid
one main midrib
unicostate
what type of plant where shoot apical meristem produce leaf primordia
dicot
more than one major vein
multicostate
without ligule what is the leaf angle?
smaller leaf angle
the blades are not divided into distinct parts, although they may be deeply lobed
simple leaves
leaves lack petioles since attached directly by its base without a stalk
sessile
are divided into leaflets, each usually with its own small petiole
compound leaves
is an extension of the petiole
rachis
plants that require
an environment that is neither too wet nor too dry
mesophytes
modified branches that arise in the axils of leaves
thorns
neither a stem nor a leaf but a small, more or less slender, sharp outgrowth from the cortex and epidermis
prickle
membranous outgrowth at base of blade of most grasses
ligule
hinge for blade to project at an angle from the stem
auricle
helps in positioning the leaf
auricle and appendages.
controls the opening and closing of leaflets
pulvini
leaf sheath and laminar joint is =
collar
types of simple leaf
obtuse, palmate, cordate, round, reniform
what is the stimuli of makahiya plant?
touch
do compound leaf has node and internode?
none
petioles attached to middle of blade
peltate
swollen area at leaf base and allows movement as response to stimuli
Pulvinus
leaflets attach at same point
palmately compound
leaflets form in pairs along central stalk (rachis)
pinnately compound
sessile leaves surround and are pierced by stem
perfoliate
first leaves to form on axillary buds; protect axillary buds
prophyll
base of petiole and cells release enzyme; breaks cell walls causing leaf to easily drop
abscission zone
morphologically different leaves on same plant
leaf dimorphism
leaf blade of fern
frond
movement independent of stimuli
nastic movement
directional movement to/from stimuli
tropism movement
what type of movement do venus flytrap follow?
nastic movement
what type of movement do prayer plant follow?
tropism movement
thigmonasty vs thigmotropism
thigmonasty - does not involve direction, thigmotropism involves direction.
is pulvinuse nastic or tropism?
nastic
leaves for photosynthesis
foliage leaves
outer covering, arised from protoderm
epidermis
embryonic leaf for storage
cotyledon
openings in the epidermis that regulates gas exchange
stomata
outermost waxy layer and protects against drought
cuticle
plants that require a large supply of water or grow wholly or partly submerged in water
hydrophytes
plants that are adapted to arid habitats
xerophytes
dominant transpiration that accounts for water loss in plants through escape of water vapor through
stomata
Stomatal transpiration
water vapor directly diffuses through cuticle
and out to atmosphere
Cuticular Transpiration
The ground tissue of the leaf, with its large
volume of intercellular spaces and numerous chloroplasts, that is particularly specialized for photosynthesis
mesophyll
2 differentiation of mesophyll cells
palisade and spongy
between palisade and spongy mesophyll which has more chlorophyll
palisade parenchyma
stomatal distribution of dicot
scattered (kidney shaped)
stomatal distribution of monocot
rows (dumbbell shaped)
both sides have stomata
amphistomatic
stomata is only found on the abaxial side
hypostimatic
stomata is only found on the adaxial side
epistomatic
specialized parenchyma cells for photosynthesis
chlorenchyma
mesophyll region in monocot
no differentiation
mesophyll region in dicot
differentiated into two (palisade and spongy)
concentric arrangement of the mesophyll and
bundle-sheath layers in C4 plants
Kranz Anatomy
function of palisade mesophyll
absorbing light
function of spongy mesophyll
for gas exchange
What is the size and thickness of sun leaves and shade leaves?
sun leaves - smaller and thicker
shade leaves - larger and thinner
where is the location of sun leaves and shade leaves?
sun leaves at top
shade leaves at bottom
which has more chlorophyll sun leaves or shade leaves?
shade leaves have more chlorophyll
which has more rubisco, sun leaves or shade leaves?
sun leaves have more rubisco (faster carbon fixation)
what is the environment of venus fly traps
nutrient deficient
economic importance of leaves
source of nutrition, flavor, medicine and well-being, fiber, recreation.
Two small bulges in leaf development
leaf buttress
hormone responsible for leaf initiation
auxin
stimulate form of the bulge form (leaf buttress)
cytokinin
what does leaf buttress develops into?
leaf primordium
stage of leaf development primordial leaf axis is developed to petiole, midrib or rachis
primary morphogenesis
stage of leaf development where the final form and size is achieved
secondary morphogenesis
stage of leaf development where marginal meristem develop into lamina
primary morphogenesis
Expansion and elongation of the leaf occur largely by
intercalary growth
