exam 2 (lect 14,15) Flashcards
rhodophyta from which supergroup
archaeplastida
red algae forms
rhodophyta
unicell, filaments with apical growth, large blades of filaments, true parenchyma
parenchyma
meristems from which cell div can occur in any plane, 3D growth, true tissues
pseudoparenchyma
aggregation of numerous, intertwined, branched filaments that collectively form thallus
held together by mucilages
ex heribaudiella brown algae
char of red alge
5000 species
small genomes w few introns
mostly marine, few freshwater
most LACK flagelalated cells
when did red algae diverge
after glaucophytes, before green algae
photosyn in red alge
chloroplasts have no grana (unstakced) w phycobilisomes
chlorophyll a + phycobilins that help absorb Blue-green light in deep water
phycobilins in red algae
mask chlorophyll a color
red color
blue light in deep water
red algae diff from cyano
lose peptidoglycan
retain phycobilisome
unstacked thylakoid
flagellated in red algae
typically in:
1. unicell algae
2. male gametes (oogamous, diff)
limited amoeboid movement but NO flagella, passive movement in water currents
rhodelphidia
new phylum
- non-photosynthetic predators
- have flagella
- gene-rich genome w many introns
rhodelphidia impact on red algae evol
mixotropic ancestor (phagotrophy and autotrophy) multiple convergent losses of phagotrophy in nearly all archaeplastida
porphyra life cycle
biphasic (2) alternation of generation
gameophyte is genetic chimera
unisexual haploid gametophyte (male and female leaves)
gametes retained on margins of gametophytes
zygotospore in porphyra life cycle
fertilized
grow on shell substrate intro conchocelis (branched filamentous) produces conchospores
genetic chimera
porphyra
germination of conchospore
meiosis occurs so 2 types of cell genetics in each blade
discovery of prophyra life cycle
kathleen drew baker
conchocelis pahse
commercializa of aquaculture production
general polysiphonia life cycle
red algae
3 generations. most filamentous red algae
triphasic alternation of generations
gametophyte (n), carposporophyte (2n), tetrasporophyte (2n)
triphasic alt of gen polysiphonia
apparent stage is gametophyte n
gametophyte and tetrasporophyte are isomorphic (resemble, like ulva)
carposporophyte (2n) is not free living but multicell struct
tetrasporophyte
similar to gametophyte, free living
carposporophyte
not free living
surrounded by tissue from female hap
multicell struct
zygote does not immediately divide to produced spores
phytoplankton
photosyn algae and cyanobacteria suspended in bodies of fresh or saalt water
primary producer
half of plant biomass
absorb 50% of CO2 prod by humans
secondary endosymbiosis of red algae
dinoflagekkates, diatoms, haptophtes, brown algae absorbed red algae
secondary symbionts of red algae
haptophyta
coccolithophores
dinoflagellata
dinoflaggelates
bacillariophyta
diatoms
phaeophyta
brown algae
chlorophyll a
every photosyn eukaryote
chlorophyll b
accessory pigment in green algae and land plants. transfer E to chlorophyll A
chlorophyll c
accessory in marine algae, similar role to chlorophyll b
haptophyta/cocclithophores
300 sepcies marine, freshwater, terrestrial unicell and colonial autotrophic, mixotrophic chlorophyll a,c huxley discovered
haptophyte struct
2 flagella and haptonema (other cytoskeletal organelle, not for motility)
haptonema can assist with catching prey food
some covered with calcified scales called coccoliths (coccolithophorids)
cocoliths
may be secreted thru golgi bodies or at cell surface
calcium carbonate
single largest component of deep sea sediments
chalk (living sediments)
dinophyta/dinoflagellates
2000-4000 marine and freshwater unicell autotrophic (~50%) or mixotrophic or hetertrophic chlorophyll a, c
dinophyta struct
cell surface made of cellulose plates (theca, organic C)
2 flagella: one in transverse groove (around organism), one trailing
beat of flagella makes cells spin
dinoflaellates in coral
zooxanthellae
reside in endoderm of cnidarians (animals) and provide photosynthesis products, receive inorganic nutrients
coral bleaching caused by loss/explusion of zooxanthellae
bioluminescence
dinoflag
mechanical disturbance, predators, waves
light cast on predators attract other predators
alveolata member
dinoflagellates
stramenopilla member
diatoms and brown algae
stramenopiles
heterokonts
diatoms, brown algae
motile stage of life cycle has 2 distinct flagella (tinsel and whiplash)
tinsel is branch, whiplash is standard
bacillariophyta/diatoms
centric or pennate silica-based SiO2 pill boxes marine, freshwater 10K-12K species unicell or colonial 20-25% of global C fix
centric diatoms
radial symmetry, float, mainly planktonic and marine
pennate diatoms
bilateral, bottom dwelling, on vegetation, also planktonic
diatom cell wall
frustule
two overlapping halves (cell walls)
silica
asexual reproduction by cell division
life cycle of centric diatom
cyclotella
no alt of generations
gametic meiosis, diploid dominant
gametes are haploid phase
male gametes have heterokont flagella (motile)
zygote/ausospore
asexual until smaller and smaller then meiosis
diatom deposits
diatomaceaous earth
kills insects b/c of microscopic shard of glass/silica
brown algae/phaeophyta
heterokont gametes and zoospores
1500 species
mostly marine in temperate and cold waters
filamentous and morphologically complex thalli (blades)
ectocarpus
brown algae
simplest, branched filament
brown algae life cycles
mose have sporic meiosis (SAR, laminaria). conspicuous sporophyte and inconspicuous gametophyte gametic meiosis (fucus). has only sporophyte and gametes
kelps
brown algae
large, highly differentiated, sporic meiosis (alt of gen)
holdfast and bladder for buoyancy
ex. macrocystis
purple sea urchin and kelp
sea star (predator of urchin) die and inc urchin count mass mortality of red abalone (led to kelp dec)
