Question

Dikaryon formation is characteristic of
A) Ascomycetes and basidiomycetes
B) Phycomycetes and basidiomycetes
C) Ascomycetes and phycomycetes
D) Phycomycetes and zygomycetes

Answer 1

Hint: There are four classes of kingdom fungi- ascomycetes, phycomycetes, basidiomycetes, and zygomycetes. There is a special feature called dikaryon is seen in only kingdom fungi. It is a stage of a cell with 2 nuclei.

Complete answer: Ascomycetes are spore shooters or sac fungi. These fungi produce microscopic spores inside special, elongated cells or sacs known as “asci”. Reproduction takes place most commonly by the asexual method. Sexual reproduction also occurs in ascomycetes which involve dikaryon. Basidiomycetes are also known as Club fungi. These fungi produce sexual spores known as basidiospores. It shares features of Ascomycetes, like the presence of dikaryon. Dikaryon is a stage that is characterized by the presence of two nuclei in each cell. This stage develops when the fusion of the nucleus is delayed and does not immediately occur after the fusion of the cytoplasm. It is an intermediate stage in the sexual reproduction of the fungus. It is a pair of the nucleus that is not fused and is haploid. The other fungi like phycomycetes are known as algal fungi. These are the fungi with aseptate hyphae. Asexual reproduction is by the formation of zoospores. Sexual reproduction is isogamous. Zygomycetes are also known as pin molds. These are the true fungi that form extended mycelia. Sex organs are zygophores. These are also known as bread molds.
Hence, the correct answer is option A.

Note: A fungus is a eukaryotic organism that includes microorganisms like yeast, molds, etc. Fungi are heterotrophs and do not synthesize their food. Fungi are classified into four main types-
i) Ascomycetes
ii) Basidiomycetes
iii) Zygomycetes
iv) Deuteromycetes (imperfecti fungi)
The characteristic features of fungi are- hyphal wall, septum, ergosterol crystal, lipid body, etc.