Lecture 25- Plant Form and Function Flashcards
what does a stem consist of? (4)
nodes
internodes
axillary bud
apical bud
what does the axillary bud do?
produces clusters of flowers or branches
lateral branches develop from axillary or lateral buds
what does the apical bud on a plant do?
primary growth
elongation of young shoot
what occurs with apical dominance?
maintains inactivity in most axillary buds
what does the node do?
site of cellular activity
where leaves attach
where is the internode on the branch?
area between leaves
what does the petiole (stalk) do?
connects the leaf to the stem
what are the functions of a root? (3)
anchors the plant
absorbs minerals and water
stores carbohydrates
why do roots have lateral roots? ex. root hairs
increase SA so that more nutrients can be absorbed
what cells are found in the root? (6)
tracheids
parenchyma
vessel elements
companion cells
sclerenchyma cells
fiber cells
primary growth of roots occurs behind the root tip in 3 zones, what are they?
cell division
elongation
differentiation/ maturation
the primary growth of roots are in line with what in order to facilitate transport?
xylem
why is the root tip covered by a root cap? (4)
protects as the root pushes through the soil
produces slime to lubricate the dry soil
produces signals to attract beneficial microbes
senses gravity
what is the function of the shoot (stem and leaves)? (4)
photosynthesis
transpiration
transport
reproduction
there are two types of water conducting cells that die at maturity within the xylem, what are they?
tracheids (small holes)
vessel elements (large holes)
what is an example of a sugar conducting cell within the phloem?
sieve tube
what does the sieve tube consist of?
sieve plate
companion cell
how does the SAM increase stem length?
cells divide quickly at the shoot tip then get pushed down after dividing, this elongates the shoot
what are the functions of leaves? (4)
intercept light
exchange gas
dissipate heat
defend plant from herbivores and pathogens
what are the two leaf types?
simple leaf
compound leaf
what are the two types of compound leaf?
pinnate (leaves arent divided into leaflets)
palmate
what is the difference between pinnate and palmate compound leaves?
with palmate all the leaves come from one location
with pinnate the leaves are all attached along the stem
why do cacti have spines?
because there is barely anything to eat in the desert the plant needs to protect itself because it has a lot of predators
in leaf structure they have something called a mesophyll, what are the two types of mesophyll?
palisade
spongy
what do stoma do for the leaf?
allow CO2 and O2 exchange (gas exchange)
allow for water to evaporate
when is the stoma open and when is it closed? why?
open during the day
closed at night
closed at night because since its dark out there is no sun and therefore cant undergo photosynthesis, so they keep all the CO2 in
