1. Fungi
By: Sami and Sandie

2. What are Fungi? Fungi are heterotrophs They cannot make their own food
They do not ingest their food, rather, they absorb nutrients from the environment outside of its body

3. What do Fungi look like?
The most common body structures are multicellular filaments and single cells (such as yeast).
Multicellular:
Constructed out of tiny filaments called hyphae
Cells that are long and thread-like and are connected end to end.
Hyphae produce sporocarp which creates the mushroom structure
Woven mat called a mycelium located at their base
Feeding network of a fungus
Hypha are divided by the septa
Cell walls built out of chitlin
Carbohydrate

4. What are the functions of the Fungi’s structure?
The wide structure of the mycelium allows for a lot of absorption and for quick growth
The septa usually have pores large enough to allow for ribosomes, mitochondria, and nuclei to flow from cell to cell
In parasitic fungi, hyphae are mortified as haustria
Adapted for preying on animals.

5. How do Fungi reproduce?
Have two choices: asexual or sexual reproduction
Asexual:
Zoospores and autospoors located in the sporangia swim away and latch onto new areas to form new chytrids
Sporangia: main cell body
Chytrid: type of fungi. The oldest.
Sexual:
The sporangia produces structures similar to asexual zoospores that fuse with zoospores from other sporangia to form a diploid zygote.
Must come into direct physical contact to have any effect

6. What are the steps of the sexual reproduction of fungi?
Begins when hyphae from two mycelia release sexual signaling molecules called pheromones.
When the hyphae meet, they fuse together.
The union of the cytoplasm of the two mycelia is regarded as plasmogamy.
At this point the mycelium are considered to be heterokaryons (fused mycelium are still genetically different)
The next stage is called karyogamy and in this stage, the haploid nuclei contributed by the two parents fuse together.
At this point the fungi is considered a zygote.
This is the only diploid stage.
After karyogamy, the cell continues onto meiosis and germination.

7. What is the basic life cycle of a fungus?

8. What is the origin of fungi?
There is much evidence that fungi evolved from a flagellated ancestor
Due to similarities in genetic sequences, fungi are said to be related to protists, suggesting that the earliest ancestor was unicellular.
What is the origin of fungi?

9. What type of fungi is the oldest in regards to modern fungi?
The oldest ‘modern’ fungi found are those of chytrid- like forms from Russia
They are considered to be the sister group to fungi alive today
They’re aquatic and not terrestrial which means fungi probably got started in water.
They have flagellated gametes (tails) and no other fungi have this
Trait would have been lost
Cell walls are made up of both chitin and cellulose
They have flagellated spores called zoospores

10. In theory, what type of species of fungi came next?
The Zygomycota are the second oldest classification of fungi.
They were thought to be very closely related to the aquatic chrytids but a vast difference in traits contradicted this
Zygotocota fungi lack flagellated gametes and spores and have a different composition of cell walls
An example of a common zymycota is bread mold

11. What followed Zygomycota?
Glomeromycota follow Zygomycota in time on the cladogram.
Very closely related to zygomycota except for the fact that they have hyphae that push into plant roots and share mutualistic partnerships with plants

12. What followed Glomeromycota?
Ascomycota followed Glomeromycota in regards to time on the cladogram.
Their primary difference is that of the production of spores in saclike asci (which is why their nickname is sac fungi)
They are usually found to be decomposers but some are parasitic.

13. What followed Ascomycota?
Basidiomycota followed ascomycota in regards to time on the cladogram
This is what typically comes to min with the mention of fungi (mushrooms!!!)
The club-like shape of the mushroom comes from the basidium to which is where the sexual reproduction stage of karygamy occurs.
They are known to be important decomposers of wood and other plant material

14. Fungi as Decomposers?

15. Fungi as Mutualists?

16. Fungi as a Parasite?

18. What’s the ecological significance?
Ecosystem depends on decomposers and symbiontes
Dead material is recycled and returned to the soil
Without fungi, the world would be covered in alyer of dead plants and animals
Some fungi are parasitic
Help to maintain population by devouring upon particular types of plants and animals
Often used in place of chemical pesticides to protect crops
Encourages the growth of plants (specifically crops)
Humans consume several types of fungi as a food source

19. What’s the economical significance?
Commercial importance in food and drugs
Medicine:
Penicillin (the first antibiotic) is derived from a common fungus called Penicillium.
Some fungi that parasitize caterpillars has chemical compounds that have be isolated and used in treatment for cancers.
Food:
Fungi is used to aid in the growth of crops
Natural protection of crops from pests
Direct consumption by humans (ex: Portobello Mushrooms)