the plant body Flashcards
what is a plant?
multicellular eukaryotes
almost all photoautotrophs
cell walls
food storage molecules (amylose starch)
structural polysaccharide (cellulose)
sessile or stationary (can’t move once roots are set)
alternation of generations life cycle
embryo retained inside gametophyte
where and what is the shoot system?
above ground
photosynthetic leaves, stems
where and what is the root system?
below ground
non photosynthetic roots
what is the function of the shoot system
stems, leaves, buds, flowers
highly adaptive for photosynthesis and positions flowers for pollination
vegetative shoot
reproductive shoot
what is vegetative (reproduction) shoot?
stem with attached leaves and buds
bud gives rise to extention of shoot or new branching shoot
what is the reproductive shoot?
produces flowers which later develop fruits containing seeds
what is the root system functions?
usually grows below ground
anchors plant and supports upright parts
absorbs water and dissolved minerals from soil
stores carbohydrates
what are the three systems in the vascular plant body?
ground, dermal, and vascular
what is the organ/tissue system?
body structure that contains two types of tissues and have definite form and function
what is a tissue?
group of one or more types of cells and intercellular substances that function together in one or specialized task
what is the primary cell wall?
surrounds plasma membrane and cell contents
middle lamella
connects cells together made from pectin
has adhesive and elastic ability used to help glue cells together
what is cellulose microfibrils?
most abundant thing is made in cells
what is a tonoplast?
very important for storage and important for regulating the internal pressure
what is a large vacuole?
used for storage and to maintain turgor pressure against the cell wall
what is the plasmodesmata?
cytoplasmic connections between adjacent cells
tubes that connects cells
allows to exchange things with other cells
what do some plant cells have?
lignified secondary cell wall
what is lignin?
cellulose fibers anchored with lignin (stronger and more rigid)
creates waterproof barrier
resistant to decay and attack by microbes
helps plant grow taller
what is ground tissue system?
structurally simple but exhibit important differences
what is vascular tissue system?
specialized for conducting fluids
what is the dermal tissue system
protects plant surfaces
what are the types of tissues in the dermal tissue system?
parenchyma
collenchyma
sclerenchyma
what are parenchyma tissues?
thin plasma membrane
vast bulk of most plants
alive and mature, can change into different cells
jack of all trades
soft primary tissue
air spaces
metabolically active when mature
what are collenchyma tissues?
tube like, marshmallow like
main function is strength and support
has pectin to reinforce parts
flexible strength
thicker primary cell wall
what are sclerenchyma tissues?
dead when matured
lots of lignin
downside, cells can’t connect or bring things in or out
provides rigid support and protection
what are the 2 main types of sclerenchyma tissues?
sclereids
fibers
what are sclerenchyma sclereids?
protective casing
cells irregular shape, commonly found in fruit and seeds
what are sclerenchyma fibers?
for support
cells often needle shaped with pointed tips some elasticity
what are the vascular tissues?
xylem and phloem
what is the xylem?
conducts water and dissolved minerals
think, lignified secondary walls
dead when functional
hydrophobic properties
what are the two types of xylem?
tracheids
vessel members
what are tracheids?
elongated, tapered, overlapping ends
lateral connections through pits
first to evolve
like long straws
what are vessel members?
shorter, tubelike columns
lateral connections through pits and perforations
better at quickly moving water more easily blocked by air bubbles in water
what is phloem?
conducts sugars and other solutes
living when functional (some are on boarder of living)
what are sieve tube members?
joined end to end in sieve tubes
assisted by companion cells
- parenchyma cells
end walls studded with pores
how are vascular tissue organized?
into vascular bindles (can be organized in many ways)
primary phloem and xylem in each bundle
wrapped in sclerenchyma for support
lengthwise through parenchyma
what are the two major classes of flowering plants?
monocots
eudicots
what are monocots?
one cotyledon (seed leaves in plant embryo)
what are eudicots?
two cotyledons
what do eudicot vascular bundles look like?
forms a circle
- outer cortex, inner pith (storage filler)
what do monocot vascular bundles look like?
scattered throughout ground tissue of stem
don’t have cortex stem
growth in plants
indetermined growth in plants
- plant growths through life
- meristem gives rise to plant body
- plasticity of growth gives some flexibility since plants
cannot move around
how do plants grow?
increasing number of cells
increase size of cells
what is primary growth?
at the apical meristem at root and shoot tips
- self perpetuating clusters of cells
- increase height of shoot, length of roots
what is secondary growth?
lateral meristems at root and shoot tips
- self perpetuating cylinder of tissue
- increase diameter of stems and roots
what is the primary shoot system?
main stem, leaves, and buds
stems adapted to provide
- mechanical support
- house vascular tissues
- food and water storage
- buds and meristems for growth
leaves carry out photosynthesis and gas exchange
what are the parts of a stem?
nodes
internodes
terminal bud
lateral bud
what is a node?
where leaves are attached
what is an internode?
between nodes
what is a terminal bud?
at apex of main shoot
what is a lateral bud?
in leaf axil, produced branches
what is the stem organized into?
modular segments
at fundamental level, growth is very organized
what are the tree primary meristems?
protoderm
procambium
ground meristem
what is the protoderm?
produces stem’s epidermis
what is the procambium?
produces primary xylem and phloem
what is the ground meristem?
produces ground tissue
what gives rise to leaves?
leaf primordia
what do leaves adapt to?
responses to environmental and herbivore pressures
modified by selective pressures
what are three leaf modifications?
spines (protection)
tendrils (support)
trichomes (secretion)
what are tendrils?
one way that plants evolved in response selection to increase support
what is the root system?
structure is specialized for underground growth
- absorbs water and minerals
- conducts water and minerals to aerial plant parts
- anchor and support
- store nutrients produced by photosynthesis
what are the 3 types of roots?
tap root
fibrous root system
adventitious roots
what are the zones for primary root growth?
zone of cell division
- root cap (highly lignified)
- quiescent center
zone of elongation
zone of maturation
what are the 3 root vascular tissues?
exodermis
endodermis
pericycle
what is the exodermis?
outer layer of root cortex
what is the endodermis?
inner layer of root cortex
what is the pericycle?
between stele and endodermis
can function as meristem
secondary growth
plants with taller stems or wider canopies can intercept more light energy from the sun
with great energy supply for photosynthesis, has metabolic means to increase root and shoot system
- able to acquire more resources
- able to ultimately reproduce successfully
what does secondary growth do?
increase girth of roots and stems
what is the vascular cambium?
produces secondary xylem and secondary phloem
produce horizontal water transport channels (xylem rays)
what is the cork cambium?
produces cork, part of protective bark
