Protozoa & Algae Flashcards
What is a protozoa?
What is an algae?
What are protozoa & algae collectively?
What are dinoflagellates?
what are Emiliania huxleyi?
diatoms?
Single celled eukaryotes without a cell wall but are motile & like wet environments- heterotrophs
protozoa with a plastid (chloroplast) = phototrophs
protists
photosynthetic eukaryotes- algae which produce neurotoxins & strip oxygen of water killing fish but produce red blooms
algae that form blooms in oceans & shells build up on sea bed as chalk deposits- concert with lowering pH of sea
algae that accumulate silica from ocean to form glass shells around them
What are the 3 processes of evolution of eukaryotes from prokaryotic archaea?
Where can you see proof of this in modern day bacteria?
how did early archaea evolve into eukaryotes & photosynthetic eukaryotes?
how can eukaryotes acquire new genetic components?
internal membrane formation = eukaryotic cells have them & prokarya don’t
cell enlargement = eukaryotic cells much bigger
serial endosymbiosis = bioenergetic compartments of mitochondria & plastids & chloroplasts
cyano bacterium has thylakoid membranes
underwent cell enlargement = proto-eukaryote
then underwent endosymbiosis with a-proteobacterium (mitochondria) & cyanobacterium (chloroplast/plastid)
horizontal transmission- e.g of nuclei & plastids
what are the 4 major groups of protozoa?
alveolates, euglenoids, oomycetes, sarcodina
What do alveolates look like?
what are the main 3 phyla of alveolates?
what are euglenoids?
what are the 3 main types?
sac-like membrane structures filled with fluid underneath cell membrane
ciliates
sporozoans
dinoflagellates
flagellated protozoa
euglena
trypanosomes
leishmania
what are oomycetes?
what are sarcodina?
what is the amoeba’s sexual cycle?
water moulds- filamentous protozoa which can grow as fungal like hyphae
comprises the amoeba- unicellular protozoa that uses pseudopodia for locomotion & feeding
when food source runs out- aggregate & slug that undergoes differentiation into stalk structure & fruited body - fruited body contains spores which survive
what was the evolution of the first photosynthetic eukaryote?
what did the cyano transition to?
how could the cyano photosynthesise?
what did cyano secrete?
what is the problem?
how is this overcome?
what is the selective pressure on?
free living cyanobacterium engulfed by amoeba-like eukaryote & became endo-symbiont
obligate symbiosis- cyano relied on host for survival & host relied on fixed carbon & oxygen
amoeba is translucent
sugar & oxygen
cyano cell wall/membrane broken down over time by eukaryotic enzymes
cyano undertakes cell division- if rate cell replication>cell death then lots of cyano so when host replicates- will be vertically transmitted
symbiont genome
what happened to the symbiont genome?
what happened to the host genome?
what does this mean to the cyano genome?
lots of genes no longer needed- many metabolic pathways lost
mass transfer of genes from cyano to nucleus due to cyano being lysed & spillage of DNA
since lots of cyano genes are now expressed in host nucleus- no need for a duplicate in cyano so genes are lost
what are the 3 lineages produced as a result of primary endosymbiosis?
green/chlorophyta- seen in algae & plants & have pigments Chlorophyll a & b
red/rhodophyta algae in seaweed- chlorophyll a & phycobilins (red)
glaucocystophyta = chlorophyll a & phycobilins (blue)
what happened to the chloroplast cell wall in glaucosytophytes (blue algae)?
green & red?
as a result, what does this made blue algae susceptible to?
retained peptidoglycan cell wall of original gram negative cyano- therefore chloroplasts have inner, outer & cell wall
only have inner & outer membrane
antibiotics
secondary endosymbiosis—–
what is it?
explain the russian doll.
what happens to the nucleomorph? what do you end up with?
what is a nucleomorph?
how many genomes does algae have? humans?
how many genomes do chloroarachniophytes/cryptophyta have?
algae captured by phagotrophic host = allows acquiring of 2nd hand chloroplast
- algae engulfed with its chloroplast so new eukaryote has 2xnucleus, 2xmitochondria & chloroplast so nucleus & mitochondria can be lost
- genetic movement from symbiont to nucleus of host for chloroplast = gene transfer, so symbiont nucleus reduced into a nucleomorph
often lost and left with chloroplast with 4 membranes- 1 from eukaryote, 1 from algae & 2 from chloroplast
between 2 original chloroplast membranes & 2 newly formed membranes
nucleus, chloroplast, mitochondria
nucleus, mitochondria
nucleus (eukaryotic host), nucleomorph (eukaryotic alga), chloroplast (cyano), mitochondria (a proto)
how many membranes do the euglenophyta/euglena chloroplasts have?
why?
what are examples of the following secondary endosymbioses with red algae?
heterokont
haptophyte
what is the apicomplexa?
what happened?
can it be a drug target?
3
don’t feed by engulfing- latch onto cell & suck out contents so the cell membrane of the captured eukarya/algae is lost- only have 3
diatoms
emiliana (chalk)
have a plastid & of red algae origin but don’t photosynthesise
acquired chloroplast with 2nd embosybiosis with red algae but lost photosynthetic genes so plastid is colourless instead of green (ex-chloroplast)
yes- antibiotics can target bacterial RNA polymerase & bacterial ribosomes which targets the cyano derived plastid but doesn’t affect humans/animals as don’t contain plastids
what happened to some dinoflagellates?
what happens to the chloroplast?
capture a haptophyte = 3rd endosymbiosis & replaced red chloroplast with green one
let it function until wears out- no gene transfer & then goes after new prey for a new one
