Introduction to Phycology Flashcards
Why are algae important?
- > 50 oxygen released into atmosphere by algae
- Human & animal nutrition
- Production of cell wall components
- Fertiliser production
- Biological research (as model organisms).
What are the negatives of algae?
- Toxic effects
- Eutrophication
- Algal blooms.
How are algae assembled on the tree of life?
Polyphyletically.
What are macroalgae?
Seaweeds.
What are microalgae?
Phytoplankton.
What are the three major macroalgal classes?
- Red algae
- Brown algae
- Green algae.
When did algae first show up?
3.5 billion years ago.
What are the components of algal cell walls?
- Fibrillar (mostly cellulose)
- Amorphous (polysaccharides).
How can algae reproduce asexually?
- Simple fragmentation
- Propagules
- Spores.
How can algae reproduce sexually?
- Isogamy - fusion of similar gametes
- Anisogamy - fusion of dissimilar gametes.
- Oogamy sperm & egg.
Describe the haplontic life cycle of algae.
- the plant body is a gametophyte, i.e. haploid and dominant or of long duration
- the zygote is diploid and of short duration.
Describe the diplontic life cycle of algae.
- the plant body is a sporophyte, i.e. diploid and dominant or of long duration
- the gametophyte is haploid and of short duration.
What are conceptacles and receptacles and where are they found?
- Found in Fucus
- Conceptacles - entire fronds bearing reproductive structures
- Receptacles - cavities bearing
reproductive structures.
How do algal sperm cells manage to
find egg cells in the Ocean?
Sperm cells follow concentration gradient of lamoxirene to locate egg cells and mate. It functions both as a trigger for sperm release in male gametophytes and as sex attractant for sperm cells.
Give an example of unicellular algae.
Diatoms.
