Exam 2 Flashcards
eukaryote supergroup that fungi belong to
Unikonta
fungi synapomorphies
- cell walls contain chitin
- absorptive nutrition
secrete digestive enzymes that break down food then, absorb digested foods into cells
absorptive nutrition
polysaccharide carbohydrate that fungi cell walls are made of
chitin
-living off dead or decaying organic material
saprobes
importance of fungi
-decomposers
-mutualistic symbionts:mycorrhizae
-parasites/pathogens
economically useful/important to people
around plant roots that provide water and nutrient absorption for plants, plants provide fungi with carbohydrates
mycorrhizae
harmless symbiotic fungi that live inside leaves or other plant parts- make toxins that deter herbivores and defend against pathogens
endophytes
reproductive and non-productive structures composed of this; filamentous, string-like
hyphae
body of fungus, mass of hyphae
mycelium
type of hyphae that is divided
septate
type of hyphae that is undivided
coenocyte
appendages of parasitic fungi
haustoria
- flagellated spore
- mostly aquatic aprobess or parasites
Chytridiomycota (Chytrids)
- mostly in soil, coenocytic hypahe
- sporangia: asexual
- zygosporangia: sexual
- some form mycorrhizae
- common bread mold, Rhizopus
Zygomycota (zygomycetes)
arbuscular mycorrhizae formed with plants
Glomeromycota
- sac fungi and yeast
- conidia: asexual
- ascocarps: sexual
- all united by having ascus
Ascomycota (ascomycetes)
sac containing ascospores
ascus
sexual stage/fruiting body
ascocarp
asexual spores in ascomycetes
conidia
- fungi with photosynthetic symbiont; most are ascomycota
- can grow in extreme habitats
- important for soil formation
lichens
- club fungi
- important decomposers
- mutualistic mycorrhizal relationships with plant roots
- asexual reproduction via fragmentation
Basidiomycota (basidiomycetes)
large structure for sexual reproduction in basidiomycetes
basidiocarp
- site of mitosis
- basidiospores extruded to outside
basidium
importance of basidiomycota
- important decomposers
- some pathogens
- many mycorrhizae
supergroup that consists of red algae, green algae, and land plants
Archaeplastida
- unicelluar
- multicelluar: colonial, filamentous, thalloid
green algae
-chloroplasts have thylakoids stacked in grana
-chlorophyll a & b
store starch
-cell walls made of cellulose
green algae and green plants
land plant apomorphies
- apical meristems
- cuticle
- thick spore walls
- gametangia
- dependent embryos
localized region of growth
apical meristems
waxy covering that helps prevent desiccation
cuticle
prevents desiccation
thick spore walls
cases that enclose gametes and prevent desiccation
gametangia
young sporophytes contained within protective structure; multicellular, parents provides nutrients
dependent embryos
- mosses, liverworts, hornworts
- paraphyletic group
- gametophyte dominant
- motile sperm (needs water)
Bryophytes
function in gas exchange and water retention
stomata
duct system for conducting fluids and nutrients
vascular tissue
- sporophyte dominant
- lignified vascular tissue
- shoots and roots
Tracheophytes
- vascular tissue that conducts most of water and minerals and includes tracheids
- cells strengthened by lignin
xylem
tube-shaped cells in xylem
tracheids
vascular tissue that has cells arranged into tubes that distribute sugars, amino acids, and other organic products of photosynthesis
phloem
organs that increase surface area of vascular plants
leaves
leaves with single vein
microphylls
leaves with highly branched vascular system
megaphylls
modified leaves with sporangia
sporophylls
clusters of sporangia on undersides of sporophylls
sori
cone-like structures formed from groups of sporophylls
strobili
- organs that anchor vscular plants
- enable vascular plants to absorb nutrients from the soil
roots
- microphylls in whorls
- roost come out of rhizome
Spenophytes: horsetails
- paraphyletic
- have true leaves and roots
ferns
Sperrmatophyta synapomorphies
- seeds
- highly reduced gametophyte
- heterospory
- pollen and ovules
consists of embryo and nutrients surrounded by protective coat
seed
adaptive significance of seeds
- protects embryo
- nutrition of embryo
- disperses embryo
- dormancy mechanism
evolution of two spores: male spores (microspores) and female spores (megaspores)
heterospory
derived from microspores- male gametophyte enclosed within wall
pollen
consists of megasporangium, megaspore (develops into female gametophyte) and one or more protective integuments
ovule
have one integument
gymnosperm megasporangia
have 2 integuments
angiosperm megasporangia
4 clades of gymnosperms
- Cycadophyta
- Ginkgophyta
- Gnetophyta
- Coniferophyta
- most are evergreen and can carry photosynthesis year round
- needle like leaves conserve water
conifers
Angiosperm synapomorphies
- flowers
- fruits
- carpel
- double fertilization with triploid endosperm
specialized shoot with up to four types of modified leaves/ floral organs
flower
encloses flower
sepals
usually brightly colored and attract pollinators
petals
produce pollen (male)
stamens
produce ovules (female)
carpels
stalk part of the stamen
filament
sac part of the stamen where pollen is produced
anther
part of carpal where pollen is received
stigma
part of carpal leading up to stigma
style
part at the base of the carpal
ovary
contained within pollen grains produced by microsporangia of anthers
male gametophytes (angiosperms)
develops within ovule contained within ovary at base of stigma
female gamteophyte -embryo sac (angiosperms)
pollen grain that has landed on stigma germinates and pollen tube of male gametophyte grows down ovary- sperm enters through micropyle
1st stage of angiosperm life cycle
occurs when pollen tube discharges 2 sperm into female gametophyte within ovule
double fertilization
one sperm fertilizes egg, other combines with 2 nuclei in central cell of female gametophyte and initiates development of food-storing endosperm
3rd stage of angiosperm life cycle
two seed leaves of embryo within seed
cotyledons
nutritive tissue in seeds of angiosperms
triploid endosperm
seed development
after double fertilization, ovule develops into seed, ovary develops into fruit enclosing seed
transfer of pollen from anther to stigma
pollination
joint evolution of interacting species in response to natural selection imposed by each other
coevolution
plant’s ability to reject its own pollen
self-incompatibility
mature ovary
fruit
- one cotyledon
- parallel leaf venation
- atactostele
- fibrous root system
- pollen grain with one opening
- floral organs in multiples of 3
monocots
- two cotyledons
- netlike leaf venation
- vascular tissue arranged in ring
- taproot
- pollen grain with three openings
- floral organs in multiples of 4 or 5
eudicots
functions of roots
- anchoring plant
- absorbing minerals and water
- storing organic nutrients
thin lateral roots with no main root
fibrous root system
one main vertical root that gives rise to lateral roots, or branch roots
taproot system
where absorption of water and minerals occurs near; vast number of these increase surface area
root hairs
- organ consisting of alternating system of nodes
- function is to maximize photosynthesis by leaves
stem
points at which leaves are attached
nodes
segments between nodes
internodes
main photosynthetic organ of most vascular plants
leaf
joins leaf to node of stem
petiole
embryonic tissue, allow for indeterminate growth
meristems
located at tips of roots and shoots and at axillary buds of shoots
apical meristems
apical meristems elongate shoots and roots
primary growth
- lateral meristems add thickness to woody plants
- characteristic of gymnosperms and woody eudicots, but not monocots
secondary growth
parts of the root andd shoot systems produced by apical meristems that primary growth produces
primary plant body
what root tip is covered by, protects apical meristem as root pushes through soil
root cap
dome-shaped mass of dividing cells at shoot tip
shoot apical meristem
where leaves develop from along sids of apical meristem
leaf primordia
develops from meristematic cells at bases of leaf primordia
axillary buds
type of lateral meristem that adds layers of vascular tissue called secondary xylem and secondary phloem
vascular cambium
type of lateral meristem that replaces epidermis with periderm
cork cambium
consists of tissues produced by vascular cambium and cork cambium
secondary plant body
- cylinder of meristematic cells one cell layer thick
- develops from undifferentiated cells
vascular cambium
