Lifecycles Of Fungus

Question 1

Life cycle of Wheat Rust

Answer 1

1. Uredioniospores in the summer time infecting the wheat with perfect clones (n+n)
2. Teliospores form in Autumn to survive winter. Karyogamy forms (2n)
3. Basidiospores form in the spring and infect the alternate host (Barberry) (n)
4. Forms Pyciniospores which fertilizes nearby pycnia (n)
5. Hyphae grow to the underbelly of the leaf, to release Aeciaspores which go out to infect wheat (n+n)

Question 2

Life Cycle of Basidiomycota

Answer 2

1. Basidiospore germinates and produces a homokaryotic mycelium. (n)
2. Mycelium finds another compatible mycelium, the hyphae from both will fuse via plasmogamy.
3. Forms a heterokaryotic mycelium using clamp connections to keep them together (n+n)
4. Forms the basidiocarp via mitosis and the basidia will form diploid nuclei via karyogamy (2n)
5. Goes through meiosis to form 4 nuclei and then forms basidiospores (n)
6. Dispersal

Question 3

Life Cycle of Ascomycota

Answer 3

1. Ascospores germinate to make mycelia which will either enter the sexual cycle or make more conidiophores and grow the mycelia.
2. Asexual cycle. Conidiophores undergo mitosis to make conidiospores.
3. Sexual cycle. Fertilization on the protoperithecium leads to the ascogenous hypha (dikaryon), cell division and mitosis making the ascocarp.
4. Karyogamy leads to a diploid zygote
5. Meiosis to form the ascus with 4 haploid cells followed by mitosis to form ascospores.