Exam 2 Notes Flashcards
shoot
stem and leaves, flowers and buds
stem
an axis for stalks with no side structures attached, used for support and conduction
function of stems
conduction of xylem and phloem
support of leaves and other above ground parts of plants
storage
photosynthesis
origin and growth of primary tissues of stems
organization of short apical meristem amore complex than root
reason of primary growth in stems
formation of leaves
node of stem
site of attachment of leaf on stem
internode of stem
area of stem where no leaves are attached
3 basic types of organization of seed plants
- primary vascular tissues develop as a cylinder of discrete strands separated from one another by ground tissue
- primary vascular tissues appear as a more or less continuous hollow cylinder with ground tissues
- vascular bundle scattered throughout the ground tissue
pith in stem
ground system
pith in root
vascular system
what does vascular cambium give rise to in the 2 organization of stems
wood
does all 3 stem organization have a pith or cortex
no
leaf trace
extensions of vascular bundles from vascular system in stem toward the leaves
leaf gap
regions of ground tissue in vascular cylinder above area where leaf traces extend toward leaves
modifications of stems
1 stolons or runners- reproductive 2 tendrils 3 thorn 4 succulent stem 5 rhizomes 6 bulbs 7 corms 8 tubers
rhizomes stem modification
reproductive, below ground
bulbs stem modification
storage structure, mostly leaf
corms stem modification
storage mostly stem
tubers
storage below ground
secondary growth in stems
at start of each growing season primary growth occurs from apical meristem
additional secondary tissues are added via secondary meristems
is secondary growth in stem dicot, monocot, or both
dicot only
what are the secondary meristems
cork cambium and vascular cambium
vascular cambium
ring of meristemic cells that adds girth to stem
cell division to the outside produces secondary phloem and to the inside is secondary xylem (wood)
vascular rays
produced by vascular cambium
mostly parenchyma cells
pathways for lateral movement
storage areas
wood sections
cross section
radial section
tangential section
cross section of wood
right angle to long axis of stem or root
growth rings are arranged in concentric circles
rays radiate from center
radial section of wood
longitudinal cut that goes through center of stem
growth rings appear as parallel lines oriented perpendicular to rays
rays appear as sheets of cells
tangential section of wood
longitudinal cut that does not go through the center of stem
growth rings arranged in large irregular patterns of concentric “v’s”
cut at right angle to rays, reveals width and height of rays
2 sections of bark
outer bark
inner bark
outer bark
all tissues outside cork cambium
non living cork
inner bark
tissues between cork cambium and vascular cambium
tissues are living,
secondary phloem, cortex, phelloderm
conifer wood
soft woods homogenous in appearance (same) few cell types (tracheids) no vessel elements rays only 1 cell wide
angiosperm wood
hard woods
heterogenous in appearance (different)
many cell types (tracheids, vessel elements, fibers, parenchyma)
rays in TS can be more than 1 cell wide
function of secondary phloem
little secondary phloem is involved in transport of food
older sieve elements become crushed
newer sieve elements replace them
periderm
replaces epidermis as the outer protective layer formed by cork cambium
cork cells
inner walls lined with suberin and wax
highly impermeable to water and gases
at maturity cork cells are dead
phelloderm cells living at maturity
lenticels
inner tissues of stems need to exchange gases with surrounding air
accomplished by lenticels
lenticels definition
holes through periderm
bark
all tissues outside of vascular cambium
leaf
structure subtends the bud
phyllotaxy (leaf arrangement)
whorled
opposite
alternate
whorled phyllotaxy
3 or more leaves per node
opposite phyllotaxy
2 leaves per node
alternate phyllotaxy
1 leaf per node
simple leaf
blade in one piece or section
complex leaf
blade in several pieces or sections (leaflets)
function of leaves
usually the most conspicuous organ of plant
photosynthesis
what is the primary function of leaves
photosynthesis
expose large amounts of surface area
mesomorphic leaf
standard leaf
hydromorphic leaf
grow wholly or partially submerged in water
large air spaces present (aerenchyma)
thin cuticle
xeromorphic leaf
adapted to arid habitat features to conserve water thick cuticle sunken stomata often multiple epidermis, trichomes
leaf epidermis
cells compactly arranged and transparent
covered with waxy cuticle to reduce water loss
stomata can occur on both surfaces, but usually more numerous on lower side
scattered stomata on leaf
dicot
rows of stomata on leaf
monocot
mesophyll
ground tissue in leaf interior of leaf between epidermis layers large numbers of intercellular spaces large number of chloroplasts in cells area specialized for photosynthesis
palisade parenchyma
mesomorphic leaf
cells into column
long axis of cells at right angle to epidermis
usually on upper side of leaf
area for capturing light
spongy mesophyll
mesomorphic leaf
cells are irregular in shape and arrangement
generally on lower side of leaf
much intercellular space facilitates gas exchange
xeromorphic leaves
palisade parenchyma can occur on both sides of leaves
grass leaves
mesophyll cells are very similar and usually not in palisade or spongy layers
dicot leaf venation
netted
monocot leaf venation
parallel
leaf veins
both xylem and phloem extend to end of vein
phloem on lower side and xylem on upper
kranz (wreath) anatomy
“warm season”
C4 photosynthesis
large bundle sheath cells that are full of chloroplasts and closely spaced veins
C3 photosynthesis
“cool season”
smaller bundle sheath cells with few chloroplasts and widely spaced veins
epidermis of grasses
several types of cells
bulliform
bulliform
large inflated epidermal cells rolling and unrolling of leaves
sun and shade leaves
environmental factors, especially light, can have substantial effects on the size and thickness of leaves
sun leaf
small and thicker than shade leaves
due to greater development of palisade parenchyma
often multiple layers of palisade cells
shade leaf
large and thin
have fewer well defined mesophyll layers
have fewer chloroplasts than sun leaves
leaf abscission
normal separation of leaf from stem
preceded by the structural and chemical changes near base of leaf petiole
results in abscission zone
2 layers of leaf abscission
separation layer
protection layer
separation layer
on leaf side
cells swell and become gelatinous
protection layer
on stem side
composed of heavily suberized cells
leaf modifications
tendril- support spines- defense food storage leaves of bulb cabbage "head" celery leaves and leaf stalk bracts insectivorous reproductive leaves water storage arid leaves bud scales flower pot leaves window leaves
cabbage “head” leaf modification
consists of short stem with many thick overlapping leaves
celery leaves and leaf stalk leaf modification
petioles become fleshy and very thick
bracts leaf modification
floral like leaves that from at the base of flowers or inflorescence
insectivorous leaf modification
insect trapping leaves
reproductive leaves leaf modification
asexual
water storage leaf modification
leaves are succulents and specialized for water storage
arid leaves leaf modification
sunken stomate are common, thick cuticle present
hypodermis
hypodermis
layer of thickened cells below epidermis
bud scales leaf modification
modified leaves are small, hard, waxy to protect the delicate meristem inside
flower pot leaves leaf modification
leaves house ants, which bring in soil and add nitrogenous waste
adventitious roots then grow into soil
window leaves leaf modification
most of plant is buried in sand, end of leaves are transparent allows light to penetrate to mesophyll
fall colors
leaves contain several types of pigments
during the growing season chlorophyll is present in dense amounts
cooler temperatures and shorter days trigger the end of chlorophyll production
other pigments are then revealed as the leaves turn colors
flower
short stem with four whorls of modified leaves,
what is the functionof flowers
reproduction
flower parts
flowers may occur singular or in cluster
pedicel
peduncle
receptacle
cluster of flowers
inflorescent
pedicel
stalk of single flower in a inflorescence
peduncle
stalk of solitary flower or inflorescence
receptacle
swollen tip of stem on which flower rests
4 whorls of flowers
sepals
petal
androecium
gynoecium
sepals
sterile structures, green (usually) structures that enclose flowers when in bud, sometimes showy
calyx
collective term for all sepals
petals
sterile structures, often very colorful, pigments are important in attracting pollinators,
what does a monocot flower have parts in
3
what does a dicot flower have parts in
4 or 5
corolla
collective term for all petals
where are sepals and petals attached
below male and female parts
perianth
collective term for sepals and petals combined
androecium (house of man
collective term for “male” flower parts (stamens)
stamens
consists of a filament terminating in an anther
gynoecium (house of women)
carpels
carpals
main structure of flower contain ovules that develop into seeds after fertilization
organization of carpels
ovary
stigma
style
ovary
swollen base that encloses ovules
stigma
usually sticky and receives pollen
style
“neck” connecting stigma to ovary
carpals in flowers
may have more than one carpal
carpals are often fused into a compound ovary
usually share a common stigma and style
fused carpals are partitioned off into two or more locales (chambers containing ovules)
placenta
structure by which ovules are attached to the ovary walls
placentation
arrangement of placenta with an ovary
floral variation
perfect imperfect staminate carpellate monoecious dioecious incomplete complete
what is the majority of flowers
perfect
perfect flower
have both stamens and carpals
incomplete flower
either stamens or carpals are missing
staminate
male structure only
carpellate
female structure only
monoecious (one house)
both staminate and carpellate flower on the same plant
dioecous (two houses)
sexes on separate plants
example of monoecious
corn
example of dioecous
cottonwood
complete flowers
have petals, sepals, carpels, and stamens
incomplete flowers
have at least one of the 4 whorls missing
ovary position in relation to flower parts
superior
inferior
superior (hypogynous)
ovary is above the attachment of sepals, petals, and stamens
hypogynous example
tulip
superior (perigyonous)
some flowers have superior ovaries, but are fused together to form a cup-like structure
hyponthium
cuplike structure of fused together ovaries
perigynous example
cherry
inferior (epigynous)
ovary is below attachment of sepals, petals, and stamens
example of epigynous)
apple
floral symmetry
radial
bilateral
canna
radial floral symmetry
flowers are said to be regular or act in actinomorphic
example of radial flower
lily or petunia
bilateral floral symmetry
flowers are said to be irregular or zygomorphic
example of bilateral floral symmetry
pea or orchid
canna
no symmetry
corona
extra perianth whorl, interior to petals
pollination methods
flowering plants have over come the problem of being immobile (as adult plants) by using a variety of ways to achieve pollination, most of the methods ensure cross pollination between genetically unlike parents
what do flowers attract
whatever pollinates them
sight, smell, placement, time of day,
types of pollination in flowers
insect pollination beetle bee and wasp fly orchids moth and butterfly bird pollination bat pollination slug pollination wind pollination water pollination
insect pollinatation
insects feed on pollen or nectar, and in process transfer pollen to other plants of same species
allows more precise transfer of pollen
beetle pollinated flowers
flowers are large and born singularly
beetle highly developed sense of smell
flowers are white in color but highly scented
bee and wasp pollinated flowers
bees eat nectar and pollen, have specialized appendages to carry pollen and have body hairs
flowers are highly showy to attract bees, usually blue or yellow, have bilateral symmetry
also may have honey guides
fly pollinated flowers
“carrion flower” mimic smell of rotting flesh
showy colors or symmetry not needed here
orchids
have developed specific pathways into and out of flowers
insure that both stigma and anther contact pollinator
about 40% of orchids advertise a reward that’s not there
some orchids mimic insect so pollinator trys to mate with it
moth and butterfly pollinated flowers
attracted by combo of sight and smell
butterflys attracted to orange, red, active during day
moths are commonly nocturnal, flowers are often night blooming, strong scents, usually white
bird pollinated flowers
produce a lot of nectar
most birds have a poor sense of smell
most of flowers have little scent, colors are important (red)
nectar
concentrated sugar solution thick
bat pollinated flowers
tropical and subtropical areas
bats feed on nectar, fruit, and pollen
produce lots of nectar
bats feed at night, night blooming
flowers might hang down on long peduncles
bats are attracted by scent, fermenting, musty
slug and snail pollinate flowers
feed on soft vegetation
close to ground
wind pollinated flowers
dull color, no scent, no nectar, smaller or absent petals, pollen, grains are small
stigma is usually big, large, and feathery, sexes often separate
much energy is devoted to pollen production
water pollinated flowers
pollen can be transferred on water or under, is often thread like, can be in chains
benefits of animal pollinators
pollen
nectar
brood place
pollen
made of starch proteins, oils, primary attractant, cheap to make
nectar
strong sugar solution, produced in nectaries at base of carpels, rich energy source, more expensive ot make
brood place
lay eggs in ovary
fruit
have been evolved for seed dispersal
what is fruit
mature ovary of a flower
accessory fruits
might include additional tissue surrounding the ovary
fruit development
pericarp
exocarp
endocarp
mesocarp
pericarp
entire fruit wall
exocarp
outer,
mesocarp
middle
endocarp
inner layer
classification of fruit
simple
aggregate
multiple
simple fruit
develop from one pistil and one flower
pistil may be simple or compound
aggregate fruit
develop from a number of separate pistils in a single flower
individual parts of the aggregate fruit known as fruitlets
multiple fruit
consist of gynoecium of more than one flower
may also develop from an inflorescence
what can you tell about a flower from a fruit
number of carpels, placentation, ovary placement
fruit types
fleshy
dry
types of fleshy fruit
berry drupe pome pepo hesperidium
types of dry fruit
dehiscent
indehiscent
berry
many seeded structures with slimy endocarp
entire pericarp is fleshy
drupe
carpal has one seed, inner layer or endocarp is stony
pome
flesh develops from cup-like hypanthium that encloses ovary
endocarp usually papery
pepo
fleshy fruit in which outer layer is a tough hard rind
inner tissues are soft
hesperidium
modification of berry, outer layer is leathery, usually contains aromatic oils
dehiscent fruit
fruit wall breaks open at maturity to release seeds
types of dehiscent fruit
follicle
legume
capsule
silique
follicle
splits down 1 side at maturity
legume
splits down 2 sides at maturity
capsule
more than 2 side of dehiscence
silique
formed by 2 fused carpels
2 sides of fruit split from a persistent central portion
silique
long and thin
silicle
shorter and thicker
indehiscent
seeds remain in fruit after fruit has been shed
types of indehiscent fruit
achene samara cypsela caryopsis nut schizocarp
achene
single seed lies free in cavity except for attachment at one end
samara
winged achene, pericarp winged
cypsela
modification of achene, non ovarian (accessory parts included)
caryopsis (grain)
seed coat is firmly, united for fruit wall
nut
contains only one seed pericarp is hard and thick
schizocarp
fruit splits apart at maturity, into 2 or more indehiscent portions
fruit and seed dispersal
wind borne
water borne
animal borne fruits and seeds (eaten)
animal borne fruits and sees (carried)
wind borne
light and become easily air borne
often wings or silky extensions
tumbleweeds
some plants are self propulsion to shoot seed out of fruits
water borne
adapted to float
can be a waxy covering over seed
animal borne ( eaten)
usually highly colored, fruits are eaten, seeds pass through GI tract of animal
additional benefit partial digestion might help germination by weakening fruit wall or seed coat
what happens to animal born fruits and seeds (eaten) at maturity
sugar content rises, tannin decreases, fruit softens, color changes from green to yellow, red, blue or black
animal born seeds and fruits (carried)
other fruits are spread by adhering to fur or feathers have hooks, barbs, or spines.
