ch. 35 Flashcards
functions of a root (3)
1) anchors the plant
2) absorbs minerals and water
3) stores carbohydrates
what is the primary root?
the first root to emerge
what does the primary root branch end up forming?
it forms secondary and tertiary branches that improve anchorage and water absorption
characteristic of tall plants
large shoot masses with taproot system
What does a taproot develop from? What is its function?
1) develops from the primary root
2) anchors plants in the soil
What part of the root does primary absorption take place?
Tertiary roots
Cell
fundamental unit of life
tissue
Group of cells consisting of one or more cell types that perform a specialized function
organ
consists of several types of tissues that carry out particular functions
which type of plants have fibrous root systems?
Small or Trailing plants
what is a fibrous root system?
Thick mat of roots spread out beneath the soil surface
why does a root system turn into a fibrous system not a tap root system?
the primary root dies early on in development
What are root hairs?
Extension of epidermal cells
Where do root hairs form?
they form near the tip of the root
What is the function of root hairs?
They increase the absorptive surface of root
Root systems form?
mycorrhizal associations with soil hyphae
Pheumo
lung or breath
Phore
to bear
5 types of specialized roots
1) buttress
2) “strangling” aerial
3) Pneumatophores
4) storage
5) Prop roots
What is a stem?
plant organ consisting of
1) alternating system of nodes
2) internodes
Apical
at the tip or top
Axill
arm pit
_____ of the _____ causes elongation of a _________
Apical meristem, apical bud, young shoot
what is an axillary bud?
structure that can form a lateral branch, thorn, or flower
What is apical dominance?
Terminal bud (apical bud) releases auxin inhibiting growth of axillary buds
What is pruning?
Removal of the terminal bud (apical bud) allows dormant axillary buds to develop
What is the primary function of a stem?
elongate and orient shoot to maximize photosynthesis
4 types of modified stems
1) Stolon
2) Rhizome
3) Tuber
4) Corm
What are bulbs?
short stems with fleshy leaves
What are corms?
Rounded storage organs, have a base covered with scale leaves, a specialized stem
What is the difference between dicot and monocot stems?
Dicot is arranged in a disk, while monocot is scattered
where does most photosynthesis take place?
the leaf
What do leaves do? (4)
1) dissipate heat
2) intercept light
3) exchange gases
4) Defend
what does the petiole do?
joins leaf to node of the stem
monocot leaves have what type of veins
parallel
eudicot leaves have what type of veins
branching veins
4 specialized leaves
1) tendril
2) spines
3) storage leaves
4) reproductive leaves
function of tendrils (1)
support and climbing
function of spines (2)
1) protect
2) reduce water loss
function of storage leaves (1)
food and water storage
function of reproductive leaves (plantlet) (1)
asexual reproduction
3 types of tissues types for roots stems and leaves
1) dermal
2) vascular
3) ground tissues
what is dermal tissue for herbaceous plants?
epidermis
what is the dermal tissue for woody plants?
periderm
What is the function of Guard cells?
facilitate gas exchange throughout the stomata
What do vascular tissue do?
Transports materials through the plant and provides mechanical support
Dead and alive cells : xylem and phloem
xylem is made up of dead cells
phloem is made up of living cells
What is a stele?
vascular tissue of the root
What is the shape of the angiosperm’s stele?
solid central vascular cylinder
Tip for identifying ground tissue
neither dermal (outside) or vascular
What is the pith?
ground tissue internal to the vascular tissue
What is the cortex?
ground tissue external to the vascular tissue
Ground tissue includes cells specialized to carry out: (4)
1) photosynthesis
2) storage
3) support
4) transport
5 major types of plant cells
1) parenchyma
2) collenchyma
3) sclerenchyma
4) water-conducting cells of xylem
5) sugar-collecting cells of phloem
parenchyma (4)
1) thin flexible primary walls
2) large central vacuole
3) metabolic functions
4) able to divide and differentiate
What kind of walls to parenchyma have?
thin flexible primary walls
Collenchyma (4)
1) unevenly thickened primary walls
2) support young parts of plant shoot
3) living at maturity
4) provide flexible support without restraining growth
What kind of walls do collenchyma have
Unvevenly thickened primary walls
Sclerenchyma
1) thick secondary walls containing lignin, makes it rigid
2) dead at maturity
What kind of walls to sclerenchyma have?
thick secondary walls containing lignin
2 types of sclerenchyma
1) sclereids: short, irregular shape
2) fibers: long and slender arranged in threads
2 types of water-conducting cells of the xylem
1) tracheids: dead, long, thin with tapered ends.
2) vessel elements: align end to end to form long pipes, common in most angiosperm and a few gymnosperms and seedless vascular plants
water movement through tracheids
it moves through pits, thin regions lacking a secondary cell wall
water movement through vessel elements
It moves through perforation plates
sugar-conducting cells of the phloem (2)
2 types: sieve cells and sieve-tube elements
1) alive
2) lacks organelles
What type of plants have sieve cells?
in seedless vascular plants and gymnosperms
What type of plants have sieve-tube elements?
angiosperms
what are sieve plates
porous end walls between sieve tube elements
what does the nucleus and ribosome of the companion cell do
serve as adjacent sieve tube elements
What connects sieve tube elements and companion cells?
plasmodesmata
indeterminate growth
when something can grow throughtout its life
What is determinate growth
most animals and some plant organs stop growing at a certain size
What is primary growth
growing longer at the tip of roots or shoots
secondary growth (2)
vascular cambium: adds layers of secondary xylem and phloem
cork cambium: replaces epidermis with periderm
Zones where cell growth takes place (3)
1) zone of cell division
2) zone of elongation
3) zone of differentiation
3 parts of primary meristems
1) protoderm
2) ground meristem
3) procambium
longevity, life cycles (3)
1) annuals: 1 yr or less
2) biennials: 2 growing seasons
3) perennials: many years
Monocots plants will have what type of roots?
fibrous roots
How does the inside of monocot roots differ from eudicot roots
eudicot has vascular tissue shaped as X
