Eukaryotic Origins and Diversity Flashcards
What is the endosymbiotic theory?
proposes that the chloroplasts and mitochondria of eukaryotic cells were originally free-living bacteria
Compare cell size of prokaryotes and eukaryotes
prokaryote = smaller, typically 0.2 - 2.0um
eukaryote = larger, typically 10-100um
compare nucleus in prokaryote cells and eukaryote cells
only present in eukaryotes (DNA strand in prokaryotes)
compare number of chromosomes in prokaryote and eukaryote cells
prokaryotes only one chromosome, eukaryotes >1
are there membrane bound organelles in prokaryotes or eukaryotes?
eukaryotes (Golgi body, Endoplasmic reticulum etc.)
Compare cytoplasm/cytoskeleton in prokaryotes and eukaryotes
prokaryotes is no cytoskeleton, and no cytoplasmic streaming
eukaryotes have both
compare cell wall in porkaryotes and eukaryotes
prokaryotes = usually present and complex
eukaryotes = only present in plants and fungi
how does cell division occur in prokaryotes and eukaryotes?
prokaryotes = binary fission
eukaryotes = mitosis
compare sexual reproduction in prokaryptes and eukaryotes
prokarytoes = by transfer of DNA fragments
eukaryotes = meiosis
compare flagella in prokaryotes and eukaryotes
prokaryotes = simple, consists of 2 proteins
eukaryotes = complex, multiple microtubules
What are features of Archaebacteria?
prokaryote
no true nucles
unicellular
autotrophic or heterotrophic
live in extreme conditions and are chemically different from Eubacteria
what are features of Eubacteria?
prokaryote
no true nucles
unicellular
autotrophic or heterotrophic
live everywhere
‘true bacteria’
What are features of Protists?
eukaryote
true nucleus
most are unicellular
autotrophic or heterotrophic
odds and ends kingdom
can be protozoa, algae, funguslike
What are features of Fungi?
eukaryote
true nucleus
multicellular (bar yeast)
heterotrophic
digest their food outside of their bodies
WHat are features of Plants?
eukaryote
true nucleus
multicellular
autotrophic
start food chains, no life on earth without plants
WHat are the features of animals?
Eukaryote
true nucleus
multicellulat
heterotrophic
largest known kindow > 1 mill species
What are the 7 superkingdoms of eukaryotes?
Opisthokonts
Amoebozoans
Archaeplastids
Stramenophiles
Alveolates
Rhizarians
Excavates
What is endosymbiosis?
a symbiotic relationship in which one organism lives inside another organism
Where did chloroplasts come from?
were once free-living cynobacteria
What are the similarities between chloroplasts and ancestral cyanobacteria?
circular DNA
DNA sequence similar
ribosomal RNA and ribosomal proteins related
What is the second origin of chloroplasts?
from multiple lineages of chloroplasts in different photosynthetic eaukaryotes
Where are AMoebozoans found? role?
moist soils and aquatic habitats, serving as predators on other microorganisms, some parasitic influencing human health
WHat are pseudopodia?
cytoplasmic extensions for locomotion and feeding (found in species Amoeba)
What are Plasmodial Slime Molds?
type of amoebozoan
form colourful often lacy amorphic masses of protoplasm
feed on bacteria and decaying organuc matter
plasmodia generate sporangia hta produce spores for dispersal
What are cellular slime molds?
type of AMoebozoan
spend most of life cycle as amoeboid cells feeding on bacteria
starvation can cause cells to produce a chemical signal that induces 1000s of cells to aggregate into a multicellular form that can collectivley move to forage for food
can form sporangia that produce spores for dispersal
What 3 major groups fo Archaeplastids consist of?
Glaucophyta, Rhodophyta, Viridiplantae
what are Glaucocystophytes?
small lineage of single-celled algae found in freshwater
their chloroplasts retain more features of the ancestral cyanobacteria endosymbiont than other algae
What are major features of red algae?
mostly multicellular from marine environments; grow attached to rocks or other algae
What is included in the cell walls of red algae?
mucilaginous matrix - prevents colonization by other algae
what are examples of two red algal mucilages used now? for what?
Agar and carrageenin
for gelling and thickening in food and pharmaceutical industries
toothpaste, ice cream, nut milks, yoghurt, and agar
What are features of Chlorophyta (green algae)?
mostly aquatic, some terrestrial
unicellular to multicellular
some are symbiotic with lichens, sponges, coelenterates
What two lineages of green algae are associated with largest diversity?
chlorophytes and streptophytes
What common algae (plantish) types are includeed in chlorophyte branch?
seaweeds like sea lettuce
complex seaweeds found in tropical and temperate oceans
WHat is an example sea lettuce?
Ulva
What are features of Ulva?
thallus sheet-like, light green, delicate and translucent
marine; found on rock and in lower-shore rock pools, and in shallow subtidal
What are some types of Streptophyte?
Chara, Spirogyra
what are some features of Chara?
multicellular; superficially resemble plants
found in fresh water, particulalryl in limestone areas throughout the northern temperate zone
covered with calcium carbonate deposits and commonly known as stoneworts
what are some features of Spirogya?
unbranched, filamentous
helical, ribbonlike chloroplasts, many pyrenoids (starch)
common in freshwater, developing slimy filamentous green masses
What are some features of Stramenophiles?
range from unicellular to filamentous multicellular forms; mostly photosynthetic
includes diatoms, giant kelps, and other types of brown algae
What are Diatoms?
most diverse lineage of stramenophiles
responsible for 25% of photosynthesis on earth
thrive in environments that range from wet soil to open ocean
What are the two froms of Diatom?
Pennate - bilaterally symmetrical
Centric - radially symmetrical
What is diatomaceous earth?
soft, siliceous sedimentary rock representing fossilised remains of diatoms (as they accumulated in rivers, streams lakes, and oceans)
What is an example of diatomaceous earth fromation?
White Cliffs of Dover
What are some characteristics of Phaeophyta - brown algae?
unicellular to filamentous multicellular
marine, dominate rocky shores
most conspicuous seaweeds of temperate, boreal, and polar waters (e.g. kelp, rockweed)
What are the features of brown algae?
thallus 9growth form for multicellular types)
simple, relatively undifferentiated vegetative body
What is kelp? features? cell walls?
marine, compromises kelp forest
holdfast, stripe, blade (lamina)
cell walls of cellulose and algin
What is algin?
mucilaginous carbohydrate
What does algin do?
provides flexibility and toughness
reduces drying in low tide
increases bouyancy
prevents colonization by other organisms
What do we use Algin for?
stabilizer and emulsifier in foods and condiments (gelatin, pudding candy paint, medical tablets (binding agent), cosmetics
what is rockweed?
marine brown algae, found on the coasts of the North sea, the Western batic sea, and the atlantic and pacific oceans
WHat is an adaptation of rockweed?
airbladders (flotation) near ends of blades
What is Ectocarpus?
mostly marine, unbranched and filamentous brown algae. grows attached to rocks and sotnes along coasts
What are dinoflagellates responsible for?
red tides (toxic blooms in coastal water) that occur naturally because of human activities such as sewage seeps and fertilized cropland runoffs
can cause massive fish kills
What are Apicomplexans?
an exclusively parasitic group that lack locomotory organelles, except during reproductive stages, have ab apical complex. an example is malaria
What are characteristics of Excavates?
asymmetrical, single-celled, heterotrophic, with a feeding groove
What are Euglenozoa?
photosynthetic excavates
