Lab #3: Fungi

Question 1

Kingdom: Fungi

Answer 1

• multicellular
• heterotrophic
• cell walls made of chitin
• saprobes (use extracellular digestion to break down decaying organic material)
• bodies composed of strand cells called hyphae
• a group of hyphae is called mycelium
• major decomposers
• asexual reproduction by fragmentation or the production of spores
• sexual reproduction by fusion of gametes to produce gametangia

Question 2

Phylum: Chytridiomycota (Chytrids)

Answer 2

• aquatic, microscopic fungi
• multinucleate, aseptate hyphae
• produces motile gametes for sexual reproduction

ex: Allomyces

Question 3

R.O. - Allomyces

Answer 3

Domain: Eukarya, Kingdom: Fungi, Domain: Chytridiomycota, Genus: Allomyces

• live in small bodies of freshwater
• floating cluster of hyphae
• rhizoids - attach Allomyces to their food source
• saprotroph (rhizoid secretes digestive enzyme to break down food)
• male gametangia: light orange
• female gametangia: colourless or grey
• discharge papillae - openings on gametangia where gametes are released

Reproduction::

• hyphae can be haploid or diploid.
  1. Diploid hyphae: carries sporangia.
• Sporangia is thin-walled when conditions are favourable. In this case, it undergoes mitosis to make diploid zoospores, which grow into young diploid hyphae
• Sporangia is thick-walled when conditions are unfavourable. This results in meiosis, which produces haploid zoospores, that develop into haploid hyphae.

2. Mature haploid: carries gametangia

Question 4

Phylum: Zygomycota

Answer 4

• terrestrial fungi
• no motile stage
• hyphae are multinucleate and aseptate
• sexual reproduction

ex: Rhizopus

Question 5

R.O. - Rhizopus

Answer 5

Domain: Eukarya, Kingdom: Fungi, Phylum: Zygomycota, Genus: Rhizopus

• common mould that grows on baked goods
• 3 types of hyphae
  1. Stolons - forms horozontal branching network that spreads across surface of food source.
  2. Rhizoids - short, branched hyphae that anchor the Rhizopus onto its food source, and secrete digestive enzyme.
  3. Sporangiophores - upright hyphae produced by stolons, under favourable conditions, to aid in asexual reproduction.

Question 6

Phylum: Asomycota

Answer 6

• terrestrial saphotrophs, and some plant pathogens
• asocarp - protective structure formed during sexual reproduction

ex: Sordaria

Question 7

R.O. - Sordaria

Answer 7

Domain: Eukarya, Kingdom: Fungi, Phylum: Asomycota, Genus: Sordaria

• lives on dung and decaying plant matter
• mostly reproduces sexually
• the asocarp grows towards the light, so that released ascospores will land on vegetation and be consumed by heterotrophs

Question 8

Phylum: Basidiomycota

Answer 8

• large fungi
• mainly terrestrial saphrotrophs
• basidia cells produce basidiospores on the reproductive structure, the basidiocarp (cap)

ex: Agaricus bisporus

Question 9

R.O. - Agaricus bisporus

Answer 9

Domain: Eukarya, Kingdom: Fungi, Phylum: Basidiomycota, Genus: Agaricus

• vast network of branching hyphae
• reporductive structure is above ground, to aid in dispersal of spores
• releases hyphae to break down decaying organic matter in soil, to use nutrients
• reproduces sexually (hyphae fuse to form a basidiocarp - mushroom - above the soil)
• gills = basidia
• meiosis occurs within the basidium, producing basidiospores