BIOL113 M L6-L7

• Basidiomycota defining features :

  elaborate and recognisable fruiting bodies and club-like bodies that produce sexual spores. This phylum includes mushrooms, puffballs, and shelf fungi. Some form mycorrhizae and others are plant parasites.
• Zygomycota defining features

  have sporangium and form a zygospore during sexual reproduction. They also lack of hyphal cell walls except in reproductive structures. These include fast growing molds, such as those that invade breads and other food products, parasites, and commensal symbionts
• Glomeromycota:

  ability to form arbuscular mycorrhizae with plants
• Chytridiomycota:

  flagellated spores. Found in terrestrial, freshwater, and marine habitats including hydrothermal vents
• Ascyomycota:

  completely sequenced and a good model for studying genes that we have. They have large sacs called asci that contain the sexual spores. They also produce large numbers of asexual spores. This phylum can be found in marine, freshwater and terrestrial habitats.
• Which bacidiomycetes is printed on the Aotearoa 50$ note?

  Entoloma hochstetteri
• Māori gathered a specific Ascomycota parasite of caterpillars in order to use them in what traditional activity?

  Tattooing
• Glomeromycota:

  include the arbuscular mcyorrhizas that form the "wood wide web"
• Chytridiomycota:

  Single celled, the simplest of the fungi
• Basidiomycota:

  Produces club-shaped structures called basidia.
• Zygomycota:

  Have Sporangiospores that are full of spores. Bread mould is a classic example.
• Ascomycota:

  Carry spores in sacs or ascii. This phylum includes brewer's yeast.
• There is a tremendous amount of controversy over what traits were present in the Last Eukaryotic Common Ancestor (LECA). Dr Maureen O'Malley has written about this topic and suggested that not only is it important to remember that traits can be lost in many lineages (like the loss of legs in snakes) but also that ...

  horizontal gene transfer or interbreeding between the population or organisms that make up the Last Eukaryotic Common Ancestor probably contributed to the traits in various eukaryotic lineages.  
• Identify three predictions that Lynn Margulis made that would support her Serial Endosymbiosis Theory. 

  Organelles would have DNA, no intracellular intermediate of the organelles would exist, and the loss of the organelle would eliminate the metabolic processes it was performing. 
• Two hypotheses for the origin of the mitochondria were described in our lecture. One of these was the serial endosymbiont theory of eukaryogenesis which was popularised by Lynn Margulis. What was the other hypothesis ?

  The in-folding of the membranes of a prokaryotic cell that first enveloped the DNA to form the nucleus and subsequently in-folded to form the mitochondria and the plastids.
• A basidium is typically observed in the common...

  Gilled mushroom
• When evaluating evidence of the Last Eukaryotic Common Ancestor (LECA) it is common to assume that all of the traits that eukaryotes have today must have been present in LECA. Why might this assumption be incorrect?

  Traits can be lost in some lineages and have been present in the last common ancestor, like legs in snakes. 

  It is likely that horizontal gene transfer of traits has taken place since the LECA so many traits that exist today may have been gained and lost amongst eukaryotic lineages which would destroy the clear taxonomic signal that is being assumed. 
• A Basidiomycota fungus in New Zealand, Inonotus lloydii, creates distinctive honeycomb patterns in the wood of tōtara trees. The Māori term for this decay pattern is: 

  Kaikākā
• Describe fungi :

  All are eukaryotic heterotrophs that feed by absorption
• what mode of nutrient acquisition do fungi use ?

  External digestion. They secrete enzymes into their surroundings, breaking down complex organic matter into simpler compounds, which are then absorbed by the fungal cells.

  Other organisms, such as animals, typically ingest food and digest it internally using specialized digestive organs like stomachs and intestines.
• how do fungi absorb their nutrients ?

  directly through their cell walls or specialized structures called hyphae, which have high surface area for efficient nutrient absorption.

  Other organisms absorb nutrients through specialized structures in their digestive systems, such as villi and microvilli in the intestines of animals, which increase surface area for absorption.
• How does the diet of fungi differ to other organisms?

  Fungi can degrade a wide range of complex organic compounds, including cellulose, lignin, and chitin, as well as organic molecules like proteins, fats, and carbohydrates.

  Other organisms may have more specific dietary requirements and may not possess the enzymatic machinery to degrade certain complex compounds like cellulose and lignin.
• what is chitin

  the cell walls of fungi
• what is a mass of hyphae called?

  mycelium
• How else can fungi aquire nutrients (other than external digestion and absorption)

  Fungi often form symbiotic relationships with other organisms, such as mycorrhizal associations with plant roots or partnerships with algae in lichens, where they exchange nutrients.
• Describe Ophiocordyceps robertsii

  A parasitic fungus which infects caterpillars. Once infected, the fungus invades the caterpillar's body and grows within it, eventually killing the host. The fungus then emerges from the ant's body, forming a stalk-like structure called a stroma, which produces spores that are dispersed to infect other caterpillars.
• what does Mātauranga mean ?

  it is a term for the traditional knowledge of the Māori people of New Zealand.
• How was the Ophiocordyceps robertsii (āwheto) fungus used by Maori?

  North Island iwi gathered the āwheto which were dried, burnt, powdered and mixed with fat to create a deep black paste. This paste was then applied into cuts made by tattooing tools
• Why was Inonotus lloydii appreciated by māori ?

  Maori appreciated the kaikākā, referring to the decayed tōtara heartwood in old trees caused by the basidiomycota fungus, Inonotus lloydii. This fungal decay created intricate honeycomb-like patterns within the wood, making it aesthetically appealing for wood turning and carving.
• what is the serial endosymbiosis theory ?

  The theory suggests that the earliest eukaryotic cells were formed when a primitive prokaryotic host cell engulfed a smaller prokaryotic cell, such as a bacterium, in a process called endosymbiosis. Over time, this engulfed cell evolved into an organelle, such as a mitochondrion or a plastid, which provided the host cell with new metabolic capabilities, such as aerobic respiration or photosynthesis.
• what is a mycorrhizae ?

  a symbiotic association between a fungus and a plant.
• what is arbuscular mycorrhizae ?

  a type of mycorrhiza in which the symbiont fungus penetrates the cortical cells of the roots of a vascular plant forming arbuscules.
• Arbuscular mycorrhizae

  Mutualistic association formed between glomeromycota fungi and plants
• Arbuscular mycorrhizae

  1. The Fungi form arbuscules within plant root cells

  2. they extend hyphae into surrounding soil increasing nutrient absorption.

  4. absorb and transfer vital nutrients (phosphorus, nitrogen, sulfur etc..) to plant

  5. improve soil structure and help plants tolerate environmental stress

  6. form the 'wood wide web' which is network plants use to communicate signals

  7. they contribute to the overall health of the forest ecosystem
• Fungi take up nutrients

  Transfer them to the plant
• Plant provides

  Carbohydrates from photosynthesis to the fungi
• "Wood wide web"

  Network allowing plants to send signals to each-other about threats like herbivores and pathogens
• Arbuscular mycorrhizal symbiosis greatly benefits forest health
• how do glomeromycota form arbuscules ?

  by penetrating the cortical cells of the roots of a vascular plant