How do septate hypha differ from coenocytic hypha?
- -Septate hypae have a septa(figure 22.3)
- -coenocytic hapae arte multinucleated (no seperation)
How do fungi feed? Do fungi contain chitin?
- - by heterotrophy
- -secrede exoenzymes
- -mutalistic symbionts
Describe the general fungal life cycle. What stages are 2n, 1n, dikaryotic? Where does meiosis take place?
- - Sporangium/spres are 1N
- -Zygote are 2N
- -Mycelium are n+n dikaryotic
. What are some characteristics of the Chytridiomycota?
- - freshwater and terrestrial
- -saprobes or parasites
- -flagellated spores
What makes the Zygomycota unique?
- -Karyogamy occurs and may go dormant
- -when conditions are favorable,break dormancy, followed by meiosis
What are the reproductive structures of the Ascomycota? Basidiomycota?
What are endomycorrhizae and ectomycorrhizae? How does this symbiosis benefit the fungus? the plant?
- -ectomycorrhizae: the fungus wraps around the root, and its mass is often as great as that of the root itself.
- - endomycorrhizae: fungi live within the above ground parts of the plant.
- -Fungus gains sugars and amino acids
- -Plant recieves water and minerals.
What are lichens?
- Associations of a fungus with a cyanobacterium
When did animals originate?
-550 million years ago
Describe three lines of evidence that choanoflagellates are closely related to animals
- -Only organisms that have genes for signaling adhesion protiens
What are some possible causesforthe Cambrian explosion & decline of Ediacarian biota?
- -New predator/prey relationships
- -Rise in atmoshperic oxygen
- -Evolution of Hox gene complex
What are the distinguishing characteristics of animals and four key features?
- -Multicellular eukaryotes
- -Lack cell walls
Contrast radial/bilateral symmetry.
- Radial: No front and back or left and right
- Bilateral: two sided symmetry with right and left, dorsal(top) and ventral (bottom)
What are the embryonic tissues of animals?
Distinguish & give an example of an acoelomate, pseudocoelomate and coelomate animal
- -Coelom = true body cavity (analid)
- -Acoelomates = no body cavity (Platyhelminthes)
- -Psuedocoelom = body cavity derived from blastocoel rahter than mesoderm (nematode)
How do deuterostomes differ from protostomes?
Plotosomes: Blastopore develops in to mouth
Deuterostomes: Blastopore developes into the anus.