Chapter 28 Diversity In Fungi

Question 1

How do fungus species obtain nutrients?

Answer 1

• 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

Question 2

What is the basic evolutionary of fungus?

Answer 2

• 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

Question 3

What are the opisthokonts and their synapomorphies?

Answer 3

• opisthokonts are fungi, animals, and choanoflagellates

- posterior flagellum

Question 4

Characteristics unique to fungi

Answer 4

• absorptive heterotrophy

- chitin in walls

Question 5

What is the difference between unicellular and multicellular fungi?

Answer 5

• 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

Question 6

What is the the body structure of a fungus?

Answer 6

• mycelium is the body of fungus which is made of hyphae

- septae is how hyphae is divided

Question 7

What type of growth do fungus species show?

Answer 7

• 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

Question 8

How do fungi interact with their environment? What purpose do fungus serve?

Answer 8

• 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

Question 9

How are parasitic fungi classified?

Answer 9

• 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

Question 10

How do parasitic fungi obtain nutrients?

Answer 10

• 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

Question 11

Parasitic Fungus in insects

Answer 11

-they will infect a bug and make it move to a high ground so that sporangia can pop out of it and release spores

Question 12

What are pathogenic fungi?

Answer 12

• 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

Question 13

What are predatory fungus and how do they absorb nutrients?

Answer 13

• 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

Question 14

What is lichen

Answer 14

-a fungus that has a symbiotic/mutualistic relationship between a fungus, algae, and yeast

Question 15

3 bodies of lichen

Answer 15

• 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

Question 16

What is mycorrhizae and what relationship does it have with plants?

Answer 16

• fungus where plants become infected with fungi, but it’s mutualistic
• fungus recurves organic compounds/ sugars from plant
• plant gets greater amount of water because of increased surface area, can also have growth hormones and protection against pathogens

Question 17

What different types of mycorrhizae are there?

Answer 17

Endophytic: fungi that lives within above ground parts of plants, some don’t affect plants others benefit
Ectomycorrhizae: fungus wraps around the plant root, hyphae wraps around individual cells doesn’t penetrate cell walls, increases surface area of root
-Arbuscular Mycorrhizae: enters the root and penetrates the cell walls of root cells and form tree like structure inside cell wall, tend to do better than those without, it makes more chlorophyll and resist drought, high growth rates