the need for a transport system Flashcards
why do plants need water
photosynthesis to create glucose
structure/support, vacuole presses cytoplasm against cell walls for turgidity
transport for dissolved nutrients
cooling
function of waxy cuticle
prevent water loss
function of upper epidermis
thin and transparent, allow more light through chloroplast
function of palisade cells
full of green chloroplast, containing chlorophyll to trap sunlight
function of spongy mesophyll
contain lots of air spaces, allow carbon dioxide to diffuse through leaf and increase surface area
function of stomata
holes in leaf to allow carbon dioxide to diffuse in and oxygen to diffuse out
function of guard cells
open and close holes, close to prevent water loss
how does the size of plant demonstrate the need for transport system
large plants need effective transport system to move substances both up and down from top of root to topmost of leaves and stems
how does SA:V demonstrate the need for transport system
leaves are adapted to have a large SA:V for gas exchange with air
stems, trunks and roots have small SA:V, cannot rely on diffusion alone to supply cells with everything they need
how does metabolic demands demonstrate the need for transport system
non-green parts of plant cant photosynthesis
need glucose and oxygen
what materials do plants exchange and transport
carbon dioxide - photosynthesis
oxygen - respiration
water - photosynthesis, structure, transport of dissolved nutrients, cooling
organic nutrient - respiration
inorganic ions - healthy growth, making proteins, chlorophyll
what are plants categorised into
non-vascular
vascular
define cotyledons
organs that act as food stores for a developing embryo plant, and form the first leaves when the seed germinates
define monocots
plants that make seeds containing one cotyledon
define dicots
plants that make seeds containing two cotyledons
difference between monocots and dicots
different leaves, stems, roots and flowers
monocot seed lie in plants embryo
monocot one cotyledon, dicot two
define herbaceous dicots
dicot with soft tissue and relatively short lifecycle
define woody dicot
dicot with heard, lignified tissues and long life cycle
where are xylem found in roots and stem
inside
where are xylem found in leaves
above phloem tissue
what does the vascular bundle in leaf form
midrib and veins of leaf
how is the vascular bundle in roots arranged
centre
central core of xylem, in shape of X
phloem in between arms of X
provides strength to withstand the pulling forces to which roots are exposed
endodermis around vascular bundle, getting water into xylem
inside endodermis is pericycle
vascular bundle in stem
found near outer edge
non-woody, separate and discrete
woody, continuous ring in older stems, complete ring of vt under tree
provides flexibility and strength to withstand bending forces
cambium between xylem and phloem, contains meristem divide to form new xylem and phloem
