Chapter 28 Diversity In Fungi Flashcards
How do fungus species obtain nutrients?
- absorptive heterotrophy
- they secrete a digestive enzyme that breaks down materials around them and absorbs them trough their membrane
- saprobes: absorb nutrients from dead organic
- predators:hunt and trap prey
- parasite: absorb nutrients from hosts
- mutualists: beneficial relationship with other organisms
What is the basic evolutionary of fungus?
- evolved from a unicellular protist with a flagellum
- they then broke off from common ancestor into their own lineage because they developed absorptive heterotrophy and chitin in walls
What are the opisthokonts and their synapomorphies?
- opisthokonts are fungi, animals, and choanoflagellates
- posterior flagellum
Characteristics unique to fungi
- absorptive heterotrophy
- chitin in walls
What is the difference between unicellular and multicellular fungi?
- unicellular (yeasts ): free living, life stage found in many fungal groups (they have both a yeast stage and multicellular stage) survive in liquid/moist environments, absorb nutrients directly across cell membranes, reproduce by budding
- multicellular: mycelium, septae(hyphae subdivided into cell like compartments, pores allow organelles and nuclei controlled movement between compartment, coenocytic(hyphae lack septa), nuclear division within cytokinesis
What is the the body structure of a fungus?
- mycelium is the body of fungus which is made of hyphae
- septae is how hyphae is divided
What type of growth do fungus species show?
- rapid growth
- hyphal growth of mycelium can exceed 1 km per day
- widely dispersed: forage nutrients over a large area
- clumped: you see a mushroom but mycelium can be huge
- spores: spread by wind or water, mushroom is the reproductive part not the main body
- fairy rings: show how far mycelium goes
How do fungi interact with their environment? What purpose do fungus serve?
- they have a large surface area to volume ration of hyphae
- they lose water easily in dry environments, they rely on moist environment
- tolerant of hypertonic environments (has more solutes than them) ex: jelly
- can live in extreme hot or cold environments
- fungus are principle decomposers can break down stuff that bacteria can’t, helps form soil by adding minerals and nutrients, main component of earths carbon cycle
How are parasitic fungi classified?
- Facultative: prefer a host but can survive without them, can grow on living organisms and can grow to independently
- Obligate: they need a specific host because they have specialized nutritional requirements, plants or insects, hyphae invades plant via stomata wounds or epidermal cell walls
How do parasitic fungi obtain nutrients?
- hyphae branch out to expand mycelium
- Haustoria: branching projections push through cell walls into living cells, they invaginate into cell/ plasma membrane, they don’t break through it, it’s a perfect fit and they absorb nutrient or form fruiting structures, most don’t kill plant
Parasitic Fungus in insects
-they will infect a bug and make it move to a high ground so that sporangia can pop out of it and release spores
What are pathogenic fungi?
- they cause diseases
- human diseases: ringworm, athletes foot,
- plants: ergot (infects seed heads if crop plants/ black)
- amphibians: chytrid fungus thicken its skins and suffocates the frog can’t absorb nutrients through skin anymore
What are predatory fungus and how do they absorb nutrients?
- active predators
- they secrete sticky substances from hyphae and when things get stuck to them the hyphae invades spreading through the body and absorbs nutrients or it can make a constricting ring and set a trap
What is lichen
-a fungus that has a symbiotic/mutualistic relationship between a fungus, algae, and yeast
3 bodies of lichen
- crustose: looks like crust
- foliose: looks like leaves, grow parallel to substrate
- fruticose: shrub like, highly branched, grow upward like shrubs, hang in long strands from tree branches or rocks
