exam 3 Flashcards
belowground and function
root system-takes in water and nutrients from soil
aboveground and function
shoot system, harvests light and CO2, produce sugars
belowground and aboveground plants systems form what
the plant body
key functions of the root system -5
-anchor plant to the soil
-absorb ions and water from soil
-conduct water and ions to the shoot system
-obtain energy from the sugar in the shoot system
-store material produced in the shoot system for later use
root system diversity can be analyzed on three levels what are they
morphological diversity-among species
phenotypic plasticity- in response to environment- stress
modified roots- for unusual functions
2 types of appearances of roots in morphological diversity
tap roots; single, long, dominant, grows straight.
Fibrous roots; smaller roots in all directions
lifespan of roots in morphological diversity
perennial; live for many years
annual; die off early
roots stop ____ or die back in areas ___ resources in phenotypic plasticity
growing, lacking
in phenotypic plasticity identical plants may
have different root systems in diffferent environments
examples of modified roots
come above surface of the soil- storage of carbs
pneumatophores- function in gas exchange
Biennial plants- carrots and beets
in a plant body, the shoot system consists of one or more
stem and leaf
stem
vertical aboveground structure
-has nodes
and internodes
leaf
appendage that projects from stem laterally on stalk- petiole
apical and axillary bud may develop into
flowers
axillary (or lateral) buds
nodes just above site of leaf attachment
-may grow into a branch-a lateral extension of root system
apical buds
tip of each stem and branch
modified stems examples
cactus, stem is converted into a water storage organ
strawberry stolons produce new individuals above ground
rhizomes- below ground, store carbohydrates
thornd- for protection
leaf structure
photosynthesis occurs in leaves, large surface area. has 2 main structures- expanded blade, stem called petiole
leaves are also diverse and can be analyzed on what 3 levels
morphological, phenotypic, and modified leaves
type of leaf blades-4
simple leaf- one petiole and one leaf blade
compound leaf- one petiole and one blade divided into many leaflets
doubly compound leaf- one petiole and many blades divided into many leaflets
needle like leaf- very hot or very cold climates
arrangement of leaves
alternate- self explanatory
opposite- self explanatory
whorled- meet in the center but have leaves around the stem
rosette- weed on the ground- center point where every leaf extends from
modified leaves and examples - 6
bulbs- onion leaves store food
succulents- aloe vera store water
floral mimics- red poinsettia leaves attract pollinators
traps- venus fly trap
tendrils- pea tendrils aid in climbing
chloroplasts
site of photosynthesis
vacuoles
have cell sap, store water, waste and nutrients
primary cell wall and secondary
cellulose
lignin, cellulose, etc.
cytoplasm of adjacent plant cells are connected by
plasmodesmata
simple tissues
skin tissue- consists of a single cell type
complex tissue
contain several type of cells
three tissues system are found in plants
dermal tissue system
ground tissue system
vascular tissue system
dermal tissue systems
outermost tissue, complex tissue. consists of epidermal cells, guard cells, trichomes, and root hairs.
dermal tissue functions in shoots and roots
shoots; protection, gas exchange
roots; protection; absorption of water and nutrients
- protection: cuticle
- regulation of water loss and gas exchange:___
- other functions:___
1- waxy layer on surface of leaves and stems, minimize water loss, protection from viruses, bacteria, and fungal spores
2- stomata
3-trichomes- prevent water loss, coolness, secrete toxins, trap and digest insects
ground tissue systems
forms plants body, SIMPLE tissue
ground tissue consist of 3 distinct tissues
parenchyma, collenchyma, sclerenchyma
function of ground tissue systems
synthesis and storage of sugars(other carbs) - support and protection
parenchyma
most abundant, have thin celled walls. many are totipotent
totipotent
capacity to divide and develop into complete plant (stem cells)
parenchyma in leaves and in roots
in leaves- photosynthesis and gas exchange
in roots- storage of carbohydrates
collenchyma
have unevenly thickened cell walls, found under epidermis- outside of vascular tissues
-provide flexible structural support to actively growing up parts of the plant
sclerenchyma
primary cell wall: cellulose.
secondary cell wall; thick/rigid, made of lignin and cellulose.
fibers; elongated
sclereids; short, variable shape
vascular tissue system consists of 2 complex tissues, what does the xylem do
xylem; conducts water and dissolved nutrients from the root system to the shoot system
xylem structure in vascular tissue system and 2 types of water conducting cells
water conducting cells, parenchyma cells, and fibers. 2 types - tracheids; long tapered, have pits (softwood) Vessel elements; short, have perforations (hard wood)
phloem structure
sieve- tube elements; lack nuclei and are directly connected to adjacent companion cells by plasmodesmata
meristems
undifferentiated-no specialized structure or function-cells that retain ability for mitosis
apical meristems
tips of each root and shoot, responsible for primary growth.
three distinct primary (plant grows in length) apical meristems
- protoderm- dermal tissue system
- ground meristem- ground tissue system
- procambium- vascular tissue system
secondary growth __ shoots and roots
widens
secondary growth
increases width of roots and shoots, provides increased structural support
secondary growth occurs due to __ (not ___)
cambium, apical meristems
cambium
vascular cambium and cork cambium
secondary xylem
WOOD
secondary phloem+primary phloem+cork cambium+ cork cells=
BARK
gas exchange in bark occurs through small opening called ___
Lenticels
dark colored inner xylem
heartwood
light colored, outer xylem
sapwood
older, innermost secondary xylem accumulates
resins and gums
in areas with seasonality, vascular cambium stops growing during the dry or cold season. this results in
annual tree rings
most adult animals have 4 tissue types
1) Nervous tissue
(2) Muscle tissue
(3) Epithelial tissue
(4) Connective tissue
tissue
group of similar cells that work together as a unit to perform the same function
nervous tissue transmit electrical signals
action potentials
changes
in permeability of plasma
membrane
nervous tissue has dendrites which
transmit
electrical signals from adjacent
cells to neurons
axons in nervous tissue
transmit electrical
signals from neurons
to other cells
pressure potential
tendency of water to move in response to pressure
turgor pressure
incoming water causes plant cell to swell, plasma membrane pushes against cell wall
wall pressure
force exerted when rigid cell wall resists expansions of cell volume
muscle tissue- long cells, voluntary movement are and function in what
skeletal muscle, attaches to bone body movement
muscle tissue- branched cells, involuntary movement are and function in what
cardiac muscle, heart walls, pump blood
muscle tissue- tapered cells, involuntary movement are and function in what
smooth muscle, digestive tract, blood vessels
epithelial tissue
Cover the outside of the body, line surfaces of organs, and form glands
organ
structure that serves a specialized function and
consists of several tissues
gland
group of cells that secrete specific molecules
Epithelial tissues have polarity, apical side and basolateral side what is the difference
apical side; faces away from other tissues
basolateral; faces the animal’s interior
simple epithelia vs stratified
simple- single layer of cells, diffusion of gases, water, nutrients
stratified- multiple layer of cells, body protection
extracellular fibers
collagen, reticular fibers, and elastin
matrix is made up of what
extracellular fibers and other materials
connective tissue
cells loosely arranged in a liquid/jelly-like/solid matrix
dense vs loose connective tissue
dense; fibrous extracellular matrix, holds tissue together tightly
loose; soft extracellular matrix
supporting vs fluid connective tissue
supporting; firm extracellular matrix, functions in structural support and protection.
fluid; liquid extracellular matrix, functions in transport
homeostasis
Stability in chemical and physical conditions within an
organism’s cells, tissues, and organs
2 different approaches to maintaining homeostasis- regulate and conform
regulate; relatively constant internal conditions even when
the environment fluctuates; Humans at 37C
conform; internal conditions fluctuate with external
environment, Antarctic rock cod with sea water.
homeostatic system based on 3 general components
- sensor
- integrator
- effector
sensor
senses external or internal environment
e.g.: Temperature receptors in the skin
integrator
evaluates incoming sensory information,
compares it to set point, determines a response
e.g.: Hypothalamus compares the set point to the current
body temperature
effector
helps restore internal condition being monitored
* e.g.: Shivering to generate warmth or fluffing of fur to
insulate and retain heat
in Mammals, a Homeostatic System Regulates
Body Temperature Through
negative feedback
thermoregulation
- conduction
- convention
- radiation
- evaporation
thermoregulatory strategies- is an animals body temp held constant?
homeotherms; keep their body temp constant
poikilotherms; body temp changes based on environment
thermoregulation varies widely
endotherm and ectotherm
endotherm
produces adequate heat to warm its own tissue
ectotherm
relies on heat gained from the environment
honeybees use what to kill predators
heat
topor- thermoregulatory strategy
temporary drop in body temp
hibernation- thermoregulatory strategy
prolonged drop in body temp
Some animal structures conserve heat with
countercurrent heat which are
Arteries are wrapped with several small veins
Heat flows freely from warm arteries to cool veins, thus retaining heat
Countercurrent exchangers are efficient—maintain gradient between two fluids along their entire length
water potential
Potential energy of water in particular
environment, compared with potential energy of pure
water at atmospheric pressure and room temperature
in water potential net movement of water occurs as direct result of
differences in water potential from roots to shoots
water potential is the sum of which 2 factors
solute potential and pressure potential
solute potential
Tendency for water to move by osmosis in response to differences in solute concentrations.
Solutions with high concentrations of solutes have ___ solute potentials
low
hypertonic condition
h2o moves out, flaccid
vascular tissue system consists of 2 complex tissues, what does the phloem do
phloem; conducts sugars, amino acids, hormones, and other substances from roots to shoots and from shoots to roots
hypotonic solution
h2o moves in, turgid
salt adapted
species accumulate solutes in root cells,
lowering their solute potential
dry adapted
species cope by tolerating low solute
potentials.
shrubs
continue to acquire water and grow because
the solute potential of their leaves remains below the
potential of soil water
wilting
Occurs When Water Loss Leads to Loss
of Turgor Pressure
sink in bulk flow
tissue where sugar exits phloem
* developing leaves, flowers, seeds,
fruits, storage cells in roots
source in bulk flow
tissue where sugar enters phloem
* Mature leaves and stems