24.3 Ecology of Fungi

Question 1

Preferred habitats

Answer 1

Dark & Moist areas
Chytrids prefer aquatic
but most can live anywhere
Most live in forest floors
some live in dry and sandy soils like the one that causes pneumonia

Question 2

Decomposers and recyclers

Answer 2

• Release Phosphate (P) and Nitrogen (N) into the enviornment
• Digestion before ingestion
• variety of exoenzymes to digest nutrients.
  - enzymes are either released into the substrate
  - or remain bound to outside of fungal cell wall.

then protein carriers breakdown and transport the nutrients in
- movement of small molecules depend on the presence of water, therefore fungi thrive in therefore moist enviornments

Question 3

Mutualistic Relationships

Answer 3

beneficial for both organisms
an example is Fungus / Plant mycorrhiza
- vascular plant roots and symbiotic fungi
- exchanges organic compounds for water and minerals

Question 4

Ectomycorrhizae

Answer 4

• Where the fungi envelops the root in a mantle
• Hartig net of hypha extends inro the roots between cells (this is the site of metabolic exchange)
• Formed by asco/basidio/zygomycota

Question 5

Arbuscular mycorrhizae (sometimes also called endo)

Answer 5

• fungi formes arbuscules that penetrate the root cells which are shrub-like and that is where nutrient exchange occurs
• orchids are dependent on this
• Formed by glomeromycota

Question 6

Endophyte (still talking about mutualistic)

Answer 6

• lives inside the plant without damaging it
  these fungi secrete toxins that repel herbivores
  or confer resistance to enviornmental stress such as protection from infection.

Question 7

Lichens

Answer 7

• unusual & hostile enviornments
• can dry out in droughts and then reactivate
• mutualism between fungus and another photosynthetic organism (can be an alga or a bacteria)
• are sensitive to air pollution
• are sensitive to abnormal levels of nitrogen and sulfur
  
  • so are used to monitor air quality
• they’re also used as a food sourse, a shelter sources and for humans in textiles via dye.

Question 8

Body thallus of a lichen

Answer 8

• hyphae are wrapped around the photosynthetic organism
• it grows slowly
• photosynthesis provides glucose for fungi
• fungi provides shelter and safety from drought for other organism

Question 9

Soredia

Answer 9

are clusters of algal cells surrounded by mycelia
- these are dispersed by wind and water by the lichen in order to form new ones

Question 10

Fungus/Animal mutualism in athropoda

Answer 10

• fungus protects the insect and provides food
• the insect gives nutrients and spreads spores
• ants and fungi

Question 11

Fungivores

Answer 11

Some spores only germinate in animal feces and so they dont die when eaten by the animal
this is a means of dissemination and dispersal
- black truffle is this