Fungi

The Pilobolus comes under the Kingdom fungi. There are five kingdoms and kingdom fungi come on the third number. The five kingdoms are Monera, Protista, Fungi, Plantae, Animalia. The fungus is eukaryotic organisms, this means that they have a true nucleus. They produce spores and have a thalloid type of body structure. They are achlorophyllous in nature, which means that they do not have chlorophyll. They are cosmopolitan in nature. This means that they are present everywhere be it air, water, land, soil and animals and plants. The Pilobolus fungi genus is present in the sub-category of fungi that is zygomycetes. 

We will learn more about the characteristics of the Pilobolus fungi genus, their digestive system and digestive tract, their mode of nutrition and reproduction and many more. 

General Characteristics of Kingdom Fungi

The Fungi Show Some General Characteristics. They are Listed Below:

  • The body of fungi is haploid. They have a thalloid type of body structure. This means that their body is not differentiated into roots, stem and leaves. Yeast is unicellular fungi and rests all other fungi are multicellular. Hyphae are thread-like elongated structures that are present in the body of fungi.

  • The fungi grow in warm and humid places. They are cosmopolitan in nature, which means that they are present everywhere be it air, water, soil and even on the body of plants and animals. 

  • The nature of their hyphae is aseptate and multinucleate. This type of hyphae is called coenocytic hyphae. But, in the majority of the fungi, their hyphae are separate in nature. There are pores present in the septum and hence it is not continuous in nature. The simple pore is present in ascomycetes but in basidiomycetes, dolipore septum is present. 

  • Chitin and fungal cellulose are present in the cell wall of fungi. It is basically made up of acetylglucosamine that is a polysaccharide that contains nitrogenous compounds.

  • Some fungi have cell walls that are made up of cellulose. Oil and glycogen are the reserved food materials. 

  • Unicisternal Golgi bodies are present in them. Mitosis takes place in them and in this mitosis, the spindle fibres are formed intracellularly. 

  • The fungi have a heterotrophic mode of nutrition with a presence of the digestive tract. They also show the saprophytic, parasitic and symbiotic mode of nutrition. 

  • Two types of phases are present that are vegetative and reproductive phases. 

Pilobolus

The Pilobolus is present in class Zygomycetes. It is also known as conjugation fungi. The Pilobolus is a terrestrial fungus and is very rarely parasitic in nature. The hyphal walls of these fungi contain chitin and fungal cellulose. Their mycelium is coenocytic in nature which means that it is multinucleate and aseptate in nature. 

Zoospores and Plano gametes that are the motile cells are absent in the Pilobolus. They have non-motile mitospores. Their spores are formed inside the sporangia therefore they are known as sporangiospores. Sporangiophores are the special type of hyphae that are formed at the tip of the fungi. Gametangial copulation is the means by which sexual reproduction occurs in them. It is also known as conjugation. Because of this, they are also known as conjugation fungi. Multinucleate gametes are present in them and they are known as coenogametes. Zygospores are resting diploid spores that are produced in sexual reproduction. Pilobolus produce zygospores, so they are called zygomycetes. 

The zygospores are different from the oospores because for the formation of zygospore, a distinct food-laden, non-motile and large female gamete is not produced. The site of meiosis is the zygospore. This zygospore does not directly give rise to mycelium. They produce germ sporangium and are known as zygosporangium. Germ sporangium forms meiospores that are called germ pores adjacent to the digestive tract. It produces germ spores. There are often cases when the gametangia fails to fuse. In this condition, it is then surrounded by a thick wall that results in the formation of asco zygospores. 

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Mycorrhiza

It is a structure that is formed for a symbiotic association of fungi and gymnosperms. The fungus in this is associated with the roots of higher plants. They are generally the gymnosperms and angiosperms and this structure together is known as mycorrhiza. The roots of the mycorrhiza are different in their shape from the normal roots. These roots have a woolly covering on them. 

Root cap and root hairs are also absent on them. A fungus can form an association with many plants and in the same way, many plants can form an association with the fungus. Based on the location, the mycorrhiza is of two types that are ectomycorrhiza and endomycorrhiza. In ectomycorrhiza, the fungal part is external in nature. It forms a woolly covering on the external surface of the roots and thus helps in forming a network of mycelium. This network is formed in the intercellular spaces of the cortex. Basidiomycetes and zygomycetes are the majority of the fungal partners. 

In the endomycorrhiza, the hyphae are present in the tissues of the roots. It then spreads intracellularly and also intercellularly. The cell wall is broken by the fungus and it enters the cortex region. It is known as a symbiotic relationship because both partners are benefited from it. The fungal part is dependent on the cortical cells of the root for nourishment and shelter. The fungal parts help in absorbing the nitrogen, minerals, phosphorus and water from the soil. Pine trees will show stunted growth if fungi are not associated with their roots.

FAQs (Frequently Asked Questions)

1. How is Vegetative Reproduction achieved in Fungi?

Answer: It is a method of reproduction in fungi. Fragmentation, budding and fission are the three modes by which this occurs. 

  • Fragmentation: As the name suggests, in this method the mycelium gets broken down into two or more fragments. This is done by mechanical injury or some other reasons are also responsible for it. These fragments that have been broken down from the mycelium are then developed into mature fragments. 

  • Budding: In budding small outgrowths are produced like they are produced in the yeast. These buds are formed from their vegetative bodies. These buds are then cut off from the parent part and are then matured to form new individuals. 

  • Fission: The vegetative cells are simply split into two small daughter cells. 

2. How is Sexual Reproduction achieved in the Fungi?

Answer: Oospores, ascospores and basidiospores are responsible for the sexual reproduction in the fungi. Fruiting bodies are the distinct structures in which these spores are produced. Asci and basidia are present in these spores and these are non-motile in nature. The basidiospores are formed externally and ascospores are formed inside asci. 

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