Topic 18: Kingdom Fungi Flashcards
4 Characteristics of Fungi
- Hyphae and Mycelium
- Chitinous Cell Wall
- Absorptive Nutrition
- Spore Production
Hyphae
long, thread-like filaments
Mycelium
The collective network of hyphae, which increases surface area for nutrient absorption.
Chitin
A strong, flexible carbohydrate that provides structural support and protection.
Absorptive Nutrition
Secrete enzymes to break down large complex molecule. Obtain nutrients by absorbing dissolved organic compounds directly from the external environment.Can digest cellulose, lignin, chitin, and keratin.
How do fungi get nutrients?
They grow underground, using hyphae to absorb nutrients.
What do early-diverging fungi lack?
Hyphae
Yeast don’t produce …
hyphae
Coenocytic Fungi (aseptate)
Early lineages lack septa or dividing walls within their hyphae. Instead form a continuous compartment containing numerous nuclei but no dividing cell walls.
Septate Fungi
Later evolving groups, nuclear division are accompanied by the formation of septa (cross-wall) that divide the cytoplasm into separate cells.
How does Hyphae enhance nutrient absorption?
- Thin
- Grow at the tips, not width
- Maximizes surface area-volume ratio
-Protected by chitin
Is there alternation of generation in fungi?
NO
Monokaryotic
Separated nuclei in Septate hyphae
Homokaryotic
Mixed Nuclei in Coenocytic
6 Steps to Fungal Sexual Reproduction
1) Sexual Signals
2) Plasmogamy
3) Heterokaryon
4) Mitosis
5) Karyogamy
6) Meoisis
Plasmogamy
The merging of cytoplasm from two parental mycelia.
Heterokaryon
Stage in between plasmo and karyo. Where multiple genetically distinct haploid nuclei cohabit.
Karyogamy
Haploid nuclei fuse to form a diploid cell and creates a BRIEF zygote.
Asexual Reproduction
Fragmentation, Budding, Spores.
Budding
unicellular yeasts reproduces through asymmetric mitosis, where small bud cell emerges from the parent cell.
Opisthokonts Clade
Fungi, animals, and protist relatives.
Kingdom of Fungi is …
monophyletic
Dikarya
most fungi belong to this subkingdom, characterized by the formation of septate hyphae and the development of dikaryotic hyphae after plasmogamy.
- The heterkaryon continually grows.
Includes all edible mushroom.
Clade Opsthosporidia
- basal fungal lineage
- Most similar to ancestral protists
- cryptomycetes
- microsporidians
Cryptomycetes
- aquatic,
- unicellular,
- flagellated spores,
-lack chitinous cell walls, - many are parasites
Microsporidians
- spore-forming,
- unicellular parasites of animals;
- lack flagellated spores
Chytrids
Flagellated spores known as Zoospores
Zoopagomycetes:
- evolution of hyphae
-movement to terrestrial
Mucoromycetes
- Has zoospores
- Exhibits zygosporangia
Ascomycetes
- most diverse
-wood-rotting fungi - makes both sexual and asexual spores
- dikarya heterokaryon (continually grows)
Basidiomycetes
- Club shaped structures called basidia
- fruiting bodies (toadstool, mushrooms)
- decomposers
- Dikarya heterokaryon
Saprotrophs
Organisms that obtain nutrients by decomposing organic matter from dead organism or waste material
Endophytes
-fungus plant mutualism
- reside in the leaves of plants
Mycorrhizae
- fungus - plant mutualism
- fungi and plant roots
- has two main types
- Ecto = w/o penetrating
- Endo (arbuscular) = penetrating
Lichens
- mutualistic
- algae, bacteria with fungi
- protective environment
Animal Fungus mutualism
Share digestive services.
Plant-parasite
- ergot
- dutch elm disease
- blue stain fungus
Invertebrate- parasitic
Have chitin exoskeleton (which can be digested)
Vertebrate - Parasitic Fungi
outside = cutaneous mycosis
inside = systemic mycosis
Nucleariid
What fungi are the closest related to
Zoospore
Flagellated sperm in Chytrids
Zygosporangia
Dormant heterokaryon in Dikarya
Ascocarp
Specialized fruiting bodies that hold sexual spores in ascomycetes
Asci
Sac-like structures in ascocarps
Conidia
The tips of specialized hyphae conidiophores
Basidia
Club-like structure in Basidiomycetes
Basidiospore
Produced by meiosis from basidia.
