Features of kingdom fungai?
Answers
Eukaryotic
Decomposers – the best recyclers around
No chlorophyll – non photosynthetic
Most multicellular (hyphae) – some unicellular (yeast)
Non-motile
Cell walls made of chitin (kite-in) instead of cellulose like that of a plant
Are more related to animals than plant kingdom
Lack true roots, leaves and stems
Absorptive heterotrophs -Digest food externally and then absorb it
Lack of chlorophyll affects the lifestyle of fungi…
Not dependant on light
Can occupy dark habitats
Can grow in any direction
Can invade the interior of
a substrate with
absorptive filaments
Characteristics of Fungi
Now, we will look at the various characteristics of fungi kingdom.
Thallus Organisation
The plant body of true fungi is a thallus. It may be non-mycelial or mycelial. The non-mycelial forms are unicellular. However, they may form a pseudomycelium by budding. In mycelial forms, the plant body is made up of thread-like structures called hyphae(sing. hypha).
Cell Organisation
The cell wall of fungi is mainly made up of chitin and cellulose. Chitin is a polymer of N-acetyl glucosamine. On the other hand, the cellulose is nothing but a polymer of d-glucose. Besides, the cell wall may be made up of cellulose-glycogen, cellulose-chitin or polygalactosamine-galactan.
Nutrition
The fungi are achlorophyllous organisms. Hence, they cannot prepare their food. They live as heterotrophs i.e., as parasites and saprophytes. Some forms live symbiotically with other green forms.
Parasites: They usually obtain their food from a living host. A parasite could be facultative or obligate. The obligate parasites survive and settle on a living host throughout their life. The facultative parasites are saprophytes that have turned parasitic.
Saprophytes: These organisms procure their nutrition from dead and decaying organic matter. The saprophytes are either obligate or facultative. An obligate saprophyte remains saprophytic during its entire lifetime. While a facultative saprophyte is nothing but a parasite that has secondarily become saprophytic.
Symbionts: Some fungi develop in symbiotic association with the green or blue-green algae. These constitute the lichen. Here the algal component is photosynthetic. While the fungal component plays the reproductive part.
Reproduction
The fungi either reproduces vegetatively, asexually or sexually:
Vegetative Reproduction
Fragmentation: Some forms belonging to Ascomycotina and Basidiomycotina multiply by breakage of the mycelium.
Budding: Some unicelled forms multiply by budding. A bud arises as a papilla on the parent cell and then after its enlargement separates into a completely independent entity.
Fission: A few unicelled forms like yeasts and slime moulds multiply by this process.
Asexual Reproduction
Sporangiospores: These are thin-walled, non-motile spores formed in a sporangium. They may be uni-or multinucleate. On account of their structure, they are also called as aplanospores.
Zoospores: They are thin-walled, motile spores formed in a zoosporangium.
Conidia: In some fungi, the spores are not formed inside a sporangium. They are born freely on the tips of special branches called conidiophores. Thus, these spores are conidia.
Sexual reproduction: With the exception of Deuteromycotina (Fungi imperfecti), we find sexual reproduction in all groups of fungi. During sexual reproduction, the compatible nuclei show a specific behaviour which is responsible for the onset of three distinct mycelial phases. The three phases of nuclear behaviour are as under:
Plasmogamy: Fusion of two protoplasts.
Karyogamy: Fusion of two nuclei.
Meiosis: The reduction division.