Fungi (Multicellular decomposers) Questions in English

(B) The sexual cycle of fungi involves three distinct steps: plasmogamy,karyogamy,and meiosis.
$1$. Plasmogamy is the fusion of protoplasm between two motile or non-motile gametes.
$2$. Karyogamy is the fusion of two nuclei.
$3$. Meiosis occurs in the zygote resulting in haploid spores.
Therefore,meiosis always follows karyogamy,as it is the process that reduces the diploid $(2n)$ zygote back to haploid $(n)$ spores.

(D) $Albugo$ $candida$ is a parasitic fungus that causes white rust disease in mustard plants.
$Rhizopus$ is a saprophytic fungus (bread mold).
$Claviceps$ is a parasitic fungus that causes ergot disease in cereals.
$Puccinia$ is a parasitic fungus that causes rust disease in wheat.

(C) The mycelium of basidiomycetes is well-developed,branched,and septate.
In the life cycle of basidiomycetes,the mycelium can be primary (uninucleate) or secondary (binucleate).
The secondary mycelium is formed by the fusion of two vegetative or somatic cells of different strains or genotypes,resulting in a dikaryotic condition $(n+n)$.
Therefore,the mycelium is characterized as septate and branched,containing either uninucleate or binucleate cells.

(B) Fungi are eukaryotic organisms that are heterotrophic in nature.
They can be unicellular (e.g.,yeast) or multicellular (e.g.,mushrooms,molds).
The cell wall of fungi is composed of chitin,not cellulose.
Therefore,the statement that all fungi possess a purely cellulosic cell wall is incorrect.

(D) Mushrooms are the fleshy,spore-bearing fruiting bodies of a fungus.
$Agaricus$ (common button mushroom),$Morchella$ (morels),and $Truffles$ (a type of subterranean ascomycete fungus) are all widely recognized as edible fungi consumed by humans.
Therefore,all the options provided are correct.

(C) The correct matches are as follows:
$(a)$ Phycomycetes: Includes fungi like $Mucor$, $Rhizopus$, and $Albugo$. Thus, $(a)-(iv)$.
$(b)$ Ascomycetes: Includes fungi like $Yeast$ $(Saccharomyces)$, $Penicillium$, and $Aspergillus$. Thus, $(b)-(iii)$.
$(c)$ Basidiomycetes: Includes fungi like mushrooms, bracket fungi, and puff balls. Thus, $(c)-(ii)$.
$(d)$ Deuteromycetes: Known as 'fungi imperfecti', includes fungi like $Alternaria$, $Colletotrichum$, and $Trichoderma$. Thus, $(d)-(i)$.
Therefore, the correct sequence is $a-iv, b-iii, c-ii, d-i$.

(C) The correct statements for Kingdom Fungi are:
$(A)$ Fungi are heterotrophic organisms,as they cannot synthesize their own food.
$(B)$ They show a great diversity in morphology (e.g.,yeasts,molds,mushrooms) and habitat (found in air,water,soil,and on animals/plants).
$(C)$ They can show symbiotic associations with plants,such as mycorrhiza (association with roots) and lichens (association with algae).
$(D)$ In Ascomycetes and Basidiomycetes,a dikaryotic phase $(n+n)$ is observed during their life cycle.
$(E)$ Not all members are coenocytic; coenocytic mycelium (multinucleate) is characteristic of Phycomycetes,while others have septate mycelium.
Therefore,statements $(A, B, C, D)$ are correct.

(D) Parasitic fungi on mustard is $Albugo$ (a member of Phycomycetes).
$(B)$ Rust and smut diseases are caused by $Puccinia$ and $Ustilago$ (members of Basidiomycetes).
$(C)$ $Neurospora$ is extensively used in biochemical and genetic work (Ascomycetes).
$(D)$ Morels and truffles are edible delicacies (Ascomycetes).
$(E)$ $Rhizopus$ is commonly known as bread mould (Phycomycetes).
Therefore,the correct matching is $(A) \rightarrow 4, (B) \rightarrow 2, (C) \rightarrow 1, (D) \rightarrow 3, (E) \rightarrow 5$.

(A) In fungi,the sexual cycle involves three steps: plasmogamy,karyogamy,and meiosis.
In lower fungi like Phycomycetes (e.g.,$Mucor$,$Rhizopus$),plasmogamy is immediately followed by karyogamy,leading to the formation of a diploid zygote $(2n)$.
In higher fungi like Ascomycetes (e.g.,$Aspergillus$) and Basidiomycetes (e.g.,$Ustilago$,$Puccinia$),there is an intervening dikaryotic stage $(n+n)$ between plasmogamy and karyogamy,known as the dikaryophase.
Therefore,$Mucor$ is the correct answer as it belongs to the class Phycomycetes where the dikaryotic stage is absent.

(A) $Ustilago$ is an example of the class $Basidiomycetes$ (club fungi).
$Alternaria$,$Colletotrichum$,and $Trichoderma$ are all examples of the class $Deuteromycetes$ (imperfect fungi).
Therefore,$Ustilago$ is the odd one out.

(A) The correct matching is as follows:
$A$. Phycomycetes: $iii$. Albugo (Parasitic fungi on mustard).
$B$. Ascomycetes: $i$. Penicillium (Source of penicillin).
$C$. Basidiomycetes: $iv$. Puccinia (Rust fungus).
$D$. Deuteromycetes: $ii$. Alternaria (Imperfect fungi).
Therefore,the correct sequence is $(A)-(iii); (B)-(i); (C)-(iv); (D)-(ii)$.