Fungi Flashcards
What is a hyphae?
A hyphae is a chain of connected cells which are thread like.
What is mycelium?
Mycelium is a mass of hyphae.
What is chitin? Where is it found? What is it made of?
Chitin are a structural polysaccharide that are found in the cell walls and are made of carbs.
How do fungi feed?
Fungi feed through absorption because they are heterotrophic.
What are the two classifications in which Fungi can come under?
- Parasitic - feed off living matter.
- Saprophytic - feed off dead matter.
What is the main role of fungi?
Fungi is responsible for the breakdown and decay of organic matter.
How do saprotrophs feed?
They feed of off carbon from decaying sources.
How do parasites feed?
They absorb food from live hosts.
What are the two types of parasitic fungi?
- Obligate
- Facultative
What is a obligate parasite?
An obligate parasite is a type of fungi that lives on host but doesn’t kill them.
What is a facultative parasite?
A facultative parasite is a type of fungi that kills the host and feeds on the remains.
What is a lichen?
A lichen is an organism which is a combination of a fungus and is an alga.
What is Rhizoid?
They provide extra surface area for absorption of the digested material (look similar to roots).
What are stolons?
They are arial hyphen which allow rhyzopus to spread sideways.
Describe the structure of rhizopus.
It consists of threadlike structures called hyphae which are tubular with no cross walls and are multi-nucleate and each nucleus is a haploid.
How do Rhizopus reproduce asexually?
- Sporangiophores grow up from the substrate after a number of days.
- Cells within the sporangium divide by mitosis to produce spores.
- The sporangium dries out in the right conditions and open which releases many spores.
- Each spore will grow into a new hyphae and mycelium if it lands on a suitable substrate.
How do Rhizopus reproduce sexually?
- Can only occur between a plus and a minus strain.
- When hyphae from opposite strains grow close to each other, swellings grow on both strains and touch each other.
- Crosswalls form to to produce gametangia.
- The walls of the gametangia dissolve and a number of fertilisations take place producing diploid zygote nuclei.
- A zygospore forms around these nuclei, whne conditions are suitable the zygospore germinates by meiosis.
- A hypha grows out of the zygospore and produces a sporangium at the tip.
- The sporangium opens and releases many haploid spores which grow into new individuals
How does yeast reproduce asexually?
- The neuclus of a parent cell divides by mitosis. One of the daughter nuclei enters a small developing bud on the outside of the yeast cell.
- This bud can separate from the parent to become a new individual.
- In some cases, the bud does not separate, but itself can bud. In this way, long colonies of yeast can develop.
Give an example of a beneficial fungai.
- Yeast – used to make bread and alcohols (Eg. wine and beer)
- Fungai – source of food (Eg. Mushroom)
Give an example of a harmful fungai.
- Various crop attacking fungai (Eg. Corn and wheat)
- Various animal attacking fungai (Eg. Athletes foot or ringworm)
- Various fungai can spoil food (Eg. Rhizopus on bread)
