Fungi Flashcards
What are molds?
- Multicellular organisms
- Cell wall is made up of chitin
- Reproduces asexually, sexually or both
- Reproductive structure produces spores
Structure of molds
- Hyphae
- Mycelium
- Spores
- Sporangium
- Sporangiophore
- Stolon
- Rhizoids
(Structure of molds) Function of components
Hyphae:
- Vegetative hyphae - visible mass of growth on surfaces and penetrates it to digest and absorb nutrients
- Reproductive hyphae - produce spores
Mycelium:
- extend the area in which the fruiting body can acquire nutrients
Spores:
- reproductive cells
Sporangium:
- reproductive structure where spores are formed
Stolon:
- Hyphae, connecting fungal bodies
Sporangiophore:
- reproductive hyphae, supports the sporangium
Rhizoids:
- anchoring the fungus into its substrates, releasing digestive enzymes
How is the mycelium formed?
The spore germinates to form a germ tube
Germ tube differentiates, grows and develops by mitosis to produce hyphae
Hyphae group together to form a mycelium
What is yeast?
- Unicellular organism
- Cell wall is made up of chitin
- Reproduce asexually (by budding) or sexually
- Form elongated buds aka pseudohyphae
Describe budding process
A small bud arises from the parent yeast cell
The nucleus and cytoplasm divides
One of the nuclei shifts to the bud, forming a daughter yeast cell
A chain of yeast cells would form over time
- occurs when there is an abundance of nutrients in the environment
Fungal spores are able to spread easily, is this an advantage or disadvantage to humans?
Some molds species are involved in human mycotic diseases by primary cause of disease, accidental pathogens and opportunistic pathogens.
Some toxins released by some mold species can be fatal
Why is it difficult to control the spread of molds
Molds can grow on variety of surfaces
They reproduce via spores, which is easily dispersed and spread as they are small and light
Widespread dispersion makes isolation and decontamination difficult
List 3 differences between fungi and prokaryotes
Prokaryotes:
- Intracellular membrane bound organelles are absent
- Nucleus is absent
- Cell wall material: peptidoglycan
Fungi:
- Intracellular membrane bound organelles are present
- Nucleus is present
Cell wall material: chitin
List 3 similarities between fungi and eukaryotes
- Intracellular membrane-bound organelles are present
- Nucleus is present
- RIbosome size: 80S
What are the differences between saprobes and parasites?
Saprobes:
- Source of nutrients: dead organic matter
- Releases nutrients into the environment
- Does not depend on a host
Parasites:
- Source of nutrients: living cells in the host
- Does not release nutrients into the environment
- Dependent on host
Difference between facultative parasite and obligate parasite
Facultative parasites are able to live with or without a host
Obligate parasite depends on a host for survival and will die without one
Difference between ectoparasites and endoparasites
Ectoparasites live on the outside of the host while endoparasites live in the tissue/blood/organs of the host
Difference between bacterial endospore and fungal spore
Bacterial endospore:
- Dormant structure
- Present in prokaryotic bacteria
- Germinate when suitable environment conditions gets fulfilled
Fungal spore:
- Reproductive structures
- Present in eukaryotic fungi
- Are exospores that release to the exterior for sporulation
When does yeast undergo sexual reproduction?
Occurs when yeast go through high stress conditions
Haploid cells will die
Diploid cells will not die and will undergo sporulation, entering sexual reproduction and produce haploid cells
