Week 3 lecture Flashcards
just covered overlap between handout and notes
What are the 3 tissue systems?
dermal tissue (like the epidermis of us); includes modified organs like root hairs and leaf hairs
vascular tissue: contains phloem and xylem, conducts food and water and provides structure
ground tissue: packing/supporting; much of the bulk. food manufacture and storage.
What are the 3 organ systems of plants
leaves
stems
roots
3 variations of ground tissue (just name them; define later.)
parenchyma
collenchyma
sclerenchyma
What is parenchyma?
have a thin primary cell wall
found in all plant tissue systems
meristematic (stem) cells
include mesophyll cells of leaf and stem that participate in photosynthesis/storage
Dr Riley said “photosynthetic, have a vacuole, cell wall is even and thin”
What is collenchyma?
handout says:
thicker cell walls; usually elongated and packed into ropelike fibers
capable of stretching; provide mechanical support in ground tissues.
common in subepidermal regions of stems
Dr Riley said “same as parenchyma; reinforced at corners”
What is sclerenchyma?
Dr Riley said “wood tissue: lignified cell walls that displace protoplasm.
dead cells
grit in pears
for support
handout says: strengthening and supportive functions. usually dead and have lignified secondary cell walls that prevent stretching as plant grows.
List the difficulties with being a stationary organism?
difficulties: predation and herbivory, diseases, competition
What are some predictable features of plants dealing with competition and herbivory?
competition:
early accelerated growth
chemical (allelopathy)
ecological- mutualism
Herbivory: chemical defense movement (mimosa that folds up when things jump on it) physical (thorns) mimicry
List 3 forms of mimicry
Batesian: mimic something dangerous, Nettle mimic in movie (nontoxic nettle)
Muellian: things that are harmful all look spiney, sort of a summation
Automimicry: making themselves look more dangerous than they are
-imprints of false spines or plant buds that look like thorns
smells can be mimicked too
Reproduction: problem for stationary organisms and how they deal
seed plants- no need for water
-harsh environment with low population densities and don’t move= great difficulty reproducing
Rely heavily on pollinators and wind pollination –> still suffer form pollen limitation
-bad timing, wrong visitation } led to intense selection
Describe asexual reproduction in plants and why it’s common
way of foraging
expanding territories
disease susceptibility –> generally spread risk
allows hedge (unlikely pollination) --> may not put much E into it because it's not very successful
What is a mixed mating strategy
asexual runners
and
flowers
Why are flowers committed?
you can’t go back to making leaves or a stem
Describe flowers
they’re very expensive and completely determinant
sexual repro has huge benefits esp for plants with shorter lifespans
They’re tolerant of long-distance relationships because it’s hard to find a mate.
If a flowering plant can’t find a mate, what does it do? two options
hybridize with a similar plant (whatever pollen you can find.)
Selfing: own eggs accept own pollen
How do plants pick the best pollen?
Best pollen germinates first
least desirable germinates last.
Land plant innovation: stomata
epidermal cells allowing CO2 into chloroplasts and O2 out
What do plants have to spend energy on after photosynthesis to protect themselves
make antioxidants
Where does gas exchange take place in a leaf?
mesophyll
Plant enzymes and rate of photosynthesis and adaptations?
The enzymes are at the whim of the environment
they adapt by positioning leaves at different places
What things make ROS?
plasma membrane chloroplasts mitochondria peroxisome cell wall apoplasts endoplasmic reticulum
adaptations of the dermis
thicker cell wall on one side
waxy cuticle
single layer
xylem
only bring water UP
cells elongate and die (interior wood is xylem)
provides structural support
water goes from xylem to phloem to help water down the sugars
functions of vascular tissues
transport
complex tissue types
water and food transport found together –> require living cells
