THE RED AND BROWN ALGAE Flashcards
proposed phylogenetic classification puts the brown algae under
Clade Stramenopila
group of the diatoms, golden brown algae, brown algae and water molds for their presence of hairy flagella,
Supergroup Chromalveolata
comprise the most anatomically and
morphologically complex of all algae
brown algae
Majority of brown algae habitat
cold marine waters with only a few inhabiting warm water habitats
They differ from green algae and true plants in
having chlorophylls a and c and large amounts of a variety of xanthophyll pigments such as fucoxanthin, violaxanthin and diatoxanthin. Carotenes are also present.
brown algae can carry on photosynthesis at varied levels in the ocean
true
All brown algae are multicellular and exhibit alternation of haploid gametophyte and diploid sporophyte generations.
true
retain its group under Clade Rhodophyta
red algae (Division Rhodophyta)
considered closest relatives of land plants along with the green algae.
red algae (Division Rhodophyta)
are best known for the complexity of their life cycles
red algae (Division Rhodophyta)
Most red algae have three multicellular phases:
a haploid gametophyte and two diploid sporophytes
a multicellular diploid generation found in plants and algae that undergo alternation of generations.
sporophyte
vast majority of red algae are multicellular, filamentous,
membranous or foliaceous
Only a few unicellular species have ever been discovered.
true
pigments give red algae their red or pink color
Phycobilins and carotenoids
Not all red algae, however, are red. Species that do not contain as much accessory pigments are often blue-green or olive in color.
true
Many red algae species also form layers of ______ in their cell walls.
They are the coralline algae and are important in reef building.
calcium carbonate
They are the __________ and are important in reef building
coralline algae
brown algae
dichotomously branched seaweed is attached to the rocks of the intertidal
zone by a holdfast. The flattened plant body possesses a prominent “midrib” and air bladders. Two kinds of tips are often found. The vegetative tip is flattened and resembles the rest of the thallus. The reproductive tip is enlarged and contains several structures.
Fucus
reproductive tips, enlarged and contains several structures
receptacles
receptacles contain various cavities called
open to the outside environment through ostioles.
conceptacles
The conceptacles may contain only oogonia, only antheridia
or both, depending on the species.
true
(oogonia and antheridia)
gametangia
gametangia are interspersed among sterile filaments called
paraphyses
brown algae
are among the species making up the kelp forest
Laminaria
plant-like body has three main parts in laminaria:
holdfast
stipe
blades
root-like plant-like body part
anchors the thallus to the substrate
holdfast
stem-like, often hollow stalk called
stipe
provide most of the surface area for
photosynthesis
blades
Laminaria stipe has an outer layer called
both meristematic and photosynthetic.
both meristematic and photosynthetic.
cortex of ______ cells lies next to the meristoderm of laminaria
parenchyma
composed of photosynthetic cells and
mucilage ducts, each of which is surrounded by secretory cells in laminaria
meristoderm
The central region of the meristoderm is composed of__________ that have pores in their end walls and temporarily function like sieve tube members.
trumpet cells
fertile area that produce motile, haploid spores known as zoospores in laminaria
sporangia
motile, haploid spores
germinate into either male or female filamentous gametophytes
heteromorphic alternation of generation is exhibited.
zoospores
when there is a haploid gametophyte in one generation and a diploid sporophyte in another generation. Both the generations are different from each other, morphologically and genetically.
heteromorphic alternation of generation
Red Algae
filamentous body organization
evolved a triphasic life history
Polysiphonia
Brown Algae representatives
Sargassum, Padina, Turbinaria, Dictyota
Red Algae representatives
Halymenia, Gracilaria, Galaxaura, Actinotrichia, Amphiroa, Kappaphycus
Polysiphonia
first of triphasic phases is the diploid ____________ that develops from the base of the carpogonium after fertilization.
carposporophyte
Polysiphonia triphasic phases
A series of cellular duplications produce filaments that are densely
packed with protoplasm that probably nourishes the developing _______.
carposporophyte
Polysiphonia triphasic phases
The carposporophyte produces the ________ that germinates into the tetrasporophyte.
carpospore
Polysiphonia triphasic phases
forms tetraspores that germinate into the gametophyte
tetrasporophyte
Polysiphonia triphasic phases
gametophyte produces
spermatangiumand
the carpogonium, which is really an oogonium
Polysiphonia triphasic phases
After fertilization, the __________ begins its development and the cycle continues.
carposporophyte
