Lecture 21 Flashcards
Define Stramenopile and Aveolata, and explain what structures these taxa derive their names from.
Stramenopile “straw hair”
- has motile cells with 2 flagella
- one flagellum covered in stiff hairs (mastigonemes
- mastigonemes secondarily lost in some lineages
- acquired photosynthesus thru secondary endosymbiosis
Alveolates (dinoflagellates)
- unicellular
- theca - coat of armour
- two flagella
– one on a groove encircling body
– second in smaller groove perpendicular to the first
- asexual reprod
descrive stramenopile chloroplasts
Pigments
- chlorophyll a and c, carotenoid
Internal membranes
- thylakoids stacked in threes
- one stack lines inner plasma mebrane
External membrane
- four membranes
Storage
- outside of chloroplast
- oil (diatoms)
- chrysolaminaran (polysaccharide)
- Mannitol (sugar-alcohol, brown algae)
Describe diatoms
- unicellular with a 2 part cell wall
- fit together like a petri dish
- each half is a frustule
- made of silica polymers
Discuss the economic importance of diatoms, brown algae, and dinoflagellates
diatoms
- base of marine foodwebs
- large role in global carbon fixation
- frustules accumulate in sediment
Brown algae
- kelp harvested for algin
- some brown algae produce phenolic compounds, terpenes which may have medicinal applications
- kelp forests are highly productive vommunities
- support high abundance and diversity of marine life
- canopy provides shelter from predators, nursery habitat for young fish
Dinoflagellates
- coral reef symbionts
- give coral colour
- anable growth in nutrient poor tropical waters
- coral bleaching under high temp and high light
diff types of diatoms
radial centric (round)
multipolar centric diatoms (triangle)
pennate (long like penne)
how do diatoms reproduce?
asexual
triggered by critical size or environment
what are red tides
dinoflagellate blooms
- associated with warm water, high nutrient, low salinity
- may kill
