lecture 7 (Haptophytes) Flashcards
in what type of environment are haptophytes most abundant?
low nutrient waters, also polar, subpolar and temperate oceans
what is the other name for haptophytes?
prymnesiophytes
briefly describe the fossil record of haptophytes
best fossil record among algae due to the calcium carbonate plates. calcite coccoliths are well preserved in sediments
what is a haptonema and how is it different from a flagellum?
a filamentous appendage that emerges between the flagella. can be short or long.
different from a flagella because it can’t beat. it bends and coils
describe the function of a haptonema (3)
feeding: bending -> phagotrophic behaviour
collision avoidance: coiling -> sensory response to obstacles
attachment to substrates
what means of locomotion do haptophytes have?
2 smooth, equal flagella
name the different kinds of coccoliths that coccolith bearing haptophytes can have. describe differences in development
holococcoliths -> organic scales produced by golgi aparatus, secreted to the outside. calcite is deposited externally as tiny crystals that don’t interlock (messier)
heterococcoliths -> organic scales and calcite are deposited internally with the crystals and coccoliths interlocking
which motile haptophyte does not have a haptonema
genus Emiliana
what are coccoliths made of and what is the function?
calcium carbonate
function = focus light into cells, protection from photodamage, protection from pathogens, protection against grazing, buoyancy regulation, protection from physical damage
what genus of haptophyte produces slime accumulation on some beaches?
Phaeocystis
why would coccolithophorids be more severly affected by ocean acidification than other unicellular algae?
they use calcium carbonate coverings which are harder to form/dissolve in acidic oceans
what colour are coccolithophorid blooms when seen from space?
white (the calcium carbonate)
do oceans with coccolithophores or oceans with diatoms have higher carbon drawdown? why?
diatoms, since formation of calcium carbonate uses some CO2, it slows the rate of PP and carbon drawdown in coccolithophoric oceans
what are the equation(s) that represent the process of calcification? what connection is there between calcification and photosynthesis?
calcification:
CO2 + Ca+ H2O -> CaCO3 + 2H
calcification is dependent on photosynthesis for ATP and NADPH
photosynthesis does not depend on calcification for CO2
what is the net calcification equation(including HCO3 utilization)?
2HCO3+Ca-> CaCO3 + CO2 + H2O
why did we talk about the white cliffs of dover and the isle of wight during the Haptophyte lecture?
because the coccoliths of this alga have created these characteristic chalky white cliffs
describe the plastids and pigments in haptophytes
butterfly shaped plastids with 4 membranes
chl a, chl c, carotene, xanthophylls (eg. fucoxanthin, diadinoxanthin)
describe the storage molecule in haptophytes
chrysolaminaran polysaccharide (stored in vacuoles)
draw the life cycle of Emiliania huxleyi
diploid vegetative asexual cell division, also can produce haploid gametes covered with holococcolith scales which can also undergo asexual haploid vegetative cell division or fuse to form a diploid zygote which becomes the diploid vegetative cell with heterococcoliths. zygotes have holococcoliths and heterococoliths
which life stage has heterococcoliths
diploid stages (and zygote)
which life stage has holococcoliths
haploid stages (and zygote)
which life stage has hetero and holococcoliths?
the zygote
describe ecological and climatic importance of haptophytes
good source of fatty acids, can produce toxins/harmful substances, dense blooms, huge part of carbon cycle, sediment formation, and releases DMS
what is DMS and how is it important for climate?
dimethyl sulfate, volatile organic sulfur gas, a defense from UV radiation. it contributes to acid rain, cloud formation, albedo
