C3.0 Flashcards
multicellular organisms
contain specialized cells that perform special functions (tissues, organs, organ systems)
small surface area to volume ratio
longer life
plant organization : cells
perform a specific job
plant organization : tissues
group of specialized cells working together
plant organization : organs
tissues contributing to the same function
plant organization : organ system
group of organs working together
the shoot system
includes stem, leaves, buds, flowers and fruits.
also includes tubers.
contains photosynthetic organs that absorb CO2 and release O2
the root system
everything underground.
also includes aerial roots.
absorbs water and minerals from the soil.
mitosis
process of cell division where once cell divides into two cells.
cell division occurs in growth areas called meristems.
plant structure
cellulose : gives plant cell walls structure
lignin : another supportive material found in plants
dermal tissue (epidermis)
found on the outside of herbaceous plants (non-woody)
one cell thick.
produces a cuticle: a waxy covering to protect the plant from water loss & insect attack.
involved with matter and gas exchange
ground tissue
layer beneath the epidermis.
responsible for photosynthesis and food and water storage.
makes up most of the body of the plant.
some cells are tightly organized along the surface to gain aces to sunlight for photosynthesis. some cells are loosely packed to allow for storage of gases.
vascular tissue
responsible for the transportation of materials
xylem : moves water and dissolved minerals from the roots up to the rest of the plant.
phloem : distributes food and other sugars from the leaves to the rest of the plant
vascular bundles are visible on the underside of the leaf
xylem tissue
moves water and dissolved minerals.
* movement from roots to stem and leaves.
transports water and nutrients for photosynthesis.
made of long individual cells which grow holes at each end and fuse like a long straw.
xylem cells die, but leave their cell walls intact, forming a transportation network
phloem tissue
moves dissolved sugars (food)
formed with long individual sieve tube cells.
perforated ends and sides to allow transfer of nutrients by osmosis.
* companion cells located in the phloem tissue use ATP to move and transport nutrients from the source (leaves) to the sink (other parts of the plant)
photosynthesis
the leaf is a collection of tissues working together to carry out photosynthesis. the purpose of photosynthesis is to create energy.
Water + carbon dioxide -> glucose + oxygen
** 6H2O(l) + 6CO2(g) -> C6H12O6(aq) + 6O2(g)
cellular respiration
glucose + oxygen -> carbon dioxide + water + energy
C6H12O6 + 6 O2 -> CO2 + H2O + energy
chloroplast
plant cells have organelles called chloroplasts which contain a green pigment called chlorophyll.
cells containing chloroplasts are found in the ground tissue.
light energy is absorbed by chlorophyll and turned into chemical energy (food for the plant)
chloroplast : accessory pigments
chlorophyll is not the only pigment to capture light energy.
accessory pigments help protect the plant and capture the most energy possible.
when temperatures get colder in the fall chlorophyll disintegrates revealing the other pigments underneath.
photorespiration
the two processes together.
neither process can occur without the other
entry of gases into the leaf
air enters plant cells through passive diffusion.
guard cells open into ground tissue to allow for efficient gas exchange.
movement of gas depends on the concentration gradient.
stomata
the majority of stomata on a leaf are found on the underside of the leaf.
depending on conditions the guard cells will open or close.
* stomata must be open for gas exchange
* proper regulation of opening/closing is important for the survival of the plant.
opening the stoma
light hits the top of the leaf, this stimulates potassium ions to enter the guard cell by active transport.
there is now a higher concentration of K+ ions inside the cell, the cell is in a hypotonic solution.
water from the ECF flows into the cell by osmosis. cells become turgid which causes them to change shape and form an opening.
the stoma is now open
closing the stoma
when sunlight is no longer available, K+ is no longer pumped by active transport.
K+ diffuses back out of the guard cells along the concentration gradient. with more K+ ions in the ECF, the guard cells are now in a hypertonic solution.
water flows out of the guard cells by osmosis. the cells lose turgor pressure, become limp and close the stoma.
transpiration
all gas in the leaf is a dissolved into the cells by dissolving in a thin film of water.
this thin film of water causes plants to lose water vapor.
this water loss is called transpiration
adapting to environmental conditions
stomata are sensitive to environmental conditions.
- colour
- leaf size
- cuticle
unicellular organisms
all life processes occur in a single cell.
large surface area to volume ratio.
short life
palisade tissue cells
(ground tissue)
found directly below upper epidermis.
long rigid rectangular cells tightly packed together.
responsible for photosynthesis
spongy mesophyll tissue
(ground tissue)
between palisade tissue cells and lower epidermis.
loosely packed with space in between.
maximized diffusion of gases.
lenticels
while most gas exchange occurs through the stomata, openings through the bark of woody plants also allow entry of gases.
these “slashes” on the tree bark are called lenticels