Lab Mod. 4 (Plant Morphology and Cladistics) Flashcards
What makes eukaryotic organisms plants
(kingdom Plantae) [5 total clades]
use chlorophyll a and b
cell wall composed of cellulose (and more)
plastids bound by ONLY 2 plasma membranes capable of photosynthesis
store food as starch
alternation of generations (for true land plants)
what is “alternation of generations”
has a haploid multicellular gametophyte
diploid multicellular sporophyte
(different stages in life)
what are the basic adaptations for land
- ability to absorb water when it’s present and prevent water loss
- “skeletal” system to hold up leaves and stems (reach the sun)
- protective packaging for gametes and embryos, decreased reliance on the presence of water for reproduction
what are the types of tissues?
all plants are made up of
ground tissue
vascular tissue
dermal tissue
what is the function of ground tissue?
makes up majority of plant body
- parenchyma: most abundant and versatile, nondescript structure
- collenchyma: strong pliable supporting cells made of cellulose fibrils and pectin, form the veins of leaves
- sclerenchyma: contain lingin, strengthens and waterproofs the plant
what function does vascular tissue serve?
transport water and food throughout the plant
- xylem: conduct water and dissolved mineral from roots to the rest of the plant. the cells (vessels and tracheids) are dead at maturity
- phloem: moves sugars from leaves to rest of plant. the main cells are alive at maturity
what are dermal tissues for?
cover and protect the surface of the plant body
- epidermis: single layer of cells covering the outer body parts of plant. cells secrete a waxy coating called the cuticle
what is the cutivle
waxy coating that protects against water loss and invasion by microorganisms
what are trichomes
structures made of special dermal cells
can be unicellular or multicellular, many functions (stinging, befuddling insects, reflecting light)
where does mitosis occur? (mitosis- parent cell => 2 identical daughter cells)
specific locations within the plant called meristems
- apical meristems: located at the very tip of shoots/roots
- lateral meristems: thicken the plant stem (ex: vascular cambium)
vascular cambium
located between phloem and xylem in stem
- produces phloem to its outside
- produces xylem to its inside
creating tree rings
green algae
share same chloroplast structure, photosynthetic pigments, enzymes, etc because of recent common ancestor
lack all terrestrial adaptations
can be unicellular, colonial, or multicellular
bryophyte
dominant life stage = haploid gametophyte
covered in waxy coating to retain moisture
no true roots - rhizoids which anchor the moss
absorb water via diffusion through surface
no true vascular tissue
examples of bryophytes
mosses, liverworts, hornworts
bryophyte reprodcution
rely on water for sperm to find egg
sporophyte grows directly on top of gametophyte
produces single celled spores which explode from capsules
ferns (pterophyte)
waxy coating to retain water - perforated with stomates to allow the exchange of gasses
true roots
true vascular system - can grow tall/support
NO true seeds or spores
dominant stage of life = diploid sporophyte
fern reproduction
one type of multicellular gametophyte produces archegonia and antheridia
relies on water for fertilization
diploid fern sporophyte grows - briefly dependent on gametophyte
gymnosperms
woody tissue
growth in vascular cambium produces rings and girth of stem
waxy covering
stomates
true roots
how are tree rings produced?
vascular cambium produces neww xylem inside and new phloem outside - wood is the accumulationo of dead tissues
the secondary xylem accumulates, secondary phloem is eventually lost
examples of gymnosperm
conifers
redwoods
sequoias
gymnosperm reproduction
spores inside sporophytes where the gametophyte develops (no free living gametophyte)
not a true seed becasue it lacks the chambers (ovaries) that angiosperm seeds develop
“naked” seed that is multicellular package that contains diploid sporophyte and food supply
seeds develop on cones with little protection
angiosperms
- flowering plants to attract and reward pollinators/dispersers
waxy coating to prevent evaporation
stomata
true roots
vascular system
angiosperm reproduction
meiosis
mostly “perfect flower” male and female reproductive parts in same flower
male structure = stamen
female structure = pistil
the anther within the stamen produces pollen grains which are carried to the stigma in the pistil and then carried down through the rest of the pistil till it reaches the ovary and can force fertilization
angiosperm seeds
after fertilization the pistil enlarges to become the seed
no pollen tube and new pollen prevented from reaching the egg
food supply = triploid endosperm (2 from mom)
endosperm helps disseminate seeds as birds eat the seeds for the endosperm
