8 - Fungi Flashcards
How do fungi feed?
they are heterotrophs that feed by absorption of complex molecules
Do fungi have haploid or diploid nuclei
Haploid
Are fungi eukaryotic or prokaryotic?
Eukaryotic
How do fungi reproduce?
asexually and sexually
What is the cell wall of fungi made up of?
chitin and polysaccharides
What are the three types of feeding mechanisms of fungi and which are parasitic?
Saprophytes, necrophytes (parasitic) and biotrophs (parasitic)
How do necrophytes feed?
The obtain nutrients from organisms they have killed
How do biotrophs feed?
They derive nutrients from a living host
What are some differences between fungi and plants?
Fungi are heterotrophic where as plants are photoautotrophic
Fungi are filamentous where as plants are made up of boxlike cells
The have different structures of the cell wall
In fungi, nuclear mitosis takes place in the nucleus, where as in other eukaryotes the nuclear envelope breaks down
How do saprotrophs feed?
They secrete enzymes onto dead matter and feed of the broken down molecules
Why is it difficult to create antifungal drugs?
Because fungi and animals are close relatives, so it is difficult to make drugs that damage fungal cells but not human or animal cells
What are the properties of the yeast form of fungi
They are unicellular and have one nucleus They are oval or spherical They reproduce asexually They are 3-5um They can aggregate to form a colony
What are the properties of the filamentous firm of fungi?
Multicellular They form long hyphae Polarised tip growth They reproduce via spores They can form a 3D mass called mycelium They can weave together to firm complex bodies
What are dimorphic fungi?
Fungi that can exist in yeast form and filamentous form
How do yeast reproduce asexually?
by budding off a daughter cell
How do filamentous fungi reproduce asexually?
They produce light weight spores which are dispersed into the environment
What are the three types of spores produced by fungi
Condiospores, arthrosprores and sporangiospores
How do fungi reproduce sexually?
By the fusion of haploid cells from two different fungi
What are the two types of sexual reproduction carried out by fungi?
Heterothallism and homothallism
What is heterothallism?
The exchange of generic material between two different acting types
What is homothallism?
When a fungi self-fertilises to form a sexual spore
What is a dikaryon?
A fungal cell that contains two haploid nuclei
What are the three main divisions of fungi?
Zygomycetes, Ascomycetes and Basidiomycetes
How do zygomycota reproduce asexually
They produce sporangiophores from a sporangiophore which are dispersed
How do zygomycota reproduce sexually?
Two gametes fuse to produce a mature zygosporangium (2n) that then splits by meiosis. The haploid cells then produce an a sexual sporangium
What are some features of zygomycetes
They have aseptate hyphae (no cell walls in hyphae between cells)
They can produce both asexually (haploid sporangiophores) and sexually (diploid zygophores)
Most are saprophytes
They included glomus levies which are important mycorrhizal fungi (symbiotic relationship with plants)
How do ascomycetes reproduce asexually?
They form condiospores from a condiophore
How do ascomycota reproduce sexually?
Two gametes fuse, producing a dikaryon and the nuclei fuse to form a diploid cell which then divides my meiosis and these cells then reproduce by mitosis to form ascospores
What are some features of ascomycetes?
Septate hyphae They can reproduce sexually (haploid ascospores formed my meiosis then mitosis) and asexually (haploid condiospores) Most are saprophytes Some are plant pathogens Good model organisms
How do basidiomycota reproduce sexually?
Two opposite basidiospores fuse to form a dikaryon and the grow as a dikaryon to form a basidiocarp (mushroom). In the gill, The two nuclei then fuse to form a haploid cell and which divides by meiosis to form four nuclei which then bud off to form basidiospores
What are some features of basidiomycetes?
Septate hyphae
They mainly reproduce sexually (via haploid basidiospores)
They form various types of fruiting bodies (toadstools, brackets and puffballs)
Most are saprophytes
They produce edible mushrooms
Include plant pathogens
What are some features of deuteromytes
They don’t have a sexual reproduction cycle
They produce various spores (asexually)
