section 3 Flashcards
(28 cards)
unicellular organisms
life process occur in a single cell
large SA:VOL ration (good)
short life
multicellular organisms
have specialized cells that preform special functions
small SA:VOL ratio (bad)
longer life
tissues
group of specialozed cells working together
organs
tissues contributing to the same funtion
organ system
group of organs working together
shoot system
everything above ground on a plant
harvest sunlight
photosynthetic organs that absorb CO2 and release O2
root system
everything underground
absorb water and minerals from the soil
mitosis
where does cell division occur?
plan cells divide for new growth and to repair damage
- 1 cell divides into 2
growth areas called meristems
3 main types of plant tissue
dermal tissue
groun tissue
vascular tissue
dermal tissue (epidermis)
covers all herbaceous (non wood) plants; 1 cell thick
produces a cuticle, waxy covering to protect plant from water loss and insect attack
ground tissue
responsible for food and water storage
photosynthesis occurs
loosely packed for gas exchange to occur
vascular tissue
responsible for transport of materials
xylem: transports water
phloem: transports food
look at xylem and phloem notes
photosynthesis formula
where does it occur?
6CO2 + 6H2O → C6H12O6 + 6O2
chloroplasts
occurs in light, producing O2 and glucose
chloroplasts
contain green pigment; chlorophyll
light energy is absorbed by chlorophyll and turned into chemical energy (plant food)
cellular respiration formula
where does it occur
C6H12O6 + 6O2 → 6CO2 + 6H2O
cytoplasm and mitochondria
no light needed
how does a guard cell open
guard cells swell because K+ is pumped into the cell (active transport) and water follows the K+
outside wall is thinner than inside; celll bends into cresent shape
how does a guard cell close
K+ exits guard cells and water follows
mesophyll ground tissue (2 types)
define both
palisade tissue: photsynthesis, found below upper epidermis
spongy mesophyll tissue: loosely packed with space (gas exchange)
Gas exchange in plants
where else does it occur?
occurs through stomata, small pores on the leaves, where carbon dioxide enters for photosynthesis and oxygen exits
trees have “slashes” and “blisters” called lenticels
root pressure
plants actively transport minerals into root cells
water is pushed up from roots
the osmotic pressure within a root system that forces water and dissolved minerals upward into the plant’s vascular tissue
cohesion and adhesion
water molecules are attracted to each other - cohesion
water molecules stick to other substances: adhesion
water climbs up the tree
transpiration pull
evaporation of water sthroigh stomata/lenticels creates tension (transpiration pull)
this pull brings water form xylem into ground tissue
water is pulled - evaporates on leaf
pressure flow
movement of materials in and out the phloem
phototropism
plants that grow towards the light
stems: positive phototropism (follow light)
roots: negative phototropism (grow away from light)
more likely to receive solar energy for photosynthesis
