Tuesday, May 14, 2019

Fungal genetics assignment Essay Example | Topics and Well Written Essays - 2500 words

Fungal genetics assignment - Essay ExampleSome of the fungus kingdom atomic number 18 a good source of food, like some mushrooms. At the same time out(p) of these mushrooms are very poisonous and an individual who eats these mushrooms s/he may end up to death if untreated appropriately. At universal level, as kingdom Fungi are found almost in all types of environment and so they are an imortant component of the ecosystem where they take part in the decomposition of the deaying material. Initally, fungi were placed in the plant kingdom because of their similitude. Later on, it was found that they are closer to animals instead of plants. yet they have been separately baseed in their own kingdom (Fungi, 2006).The Ascomycota also known as sac fungi or ascomycetes because of their morphological resemblance. Mmbers of this division form meiotic spores called ascospores, which are envelop in a special sac-like structure called an ascus. Sseveral ascomyctes have been used for elucidat ing principles of genetics and heredity, one member of the group is Neurospora crassa.In 1927, Shear and Dodge gave a very comprehensive account of fungus Neurospora. They called it with this name because of its resemblance to nerves the striations which develop on the wall of ascospore are like nerves. They discovered the mating types A and a of this genus Neurospora and further described the life histories of three species, two eight-spored heterothallic species named N. crassa and N. sitohila and one four-spored homothallic species N. tetrasperma. (Perkins, 2002) Their explanation of the characteristics related to thallism was ground on their work on nucleus of these species. In fact, there is programming of ascus development in N. tetrasperma in a way that each of the four ascospores encloses two nuclei of the opposite mating type. So there is self-fertilisation of single-ascospores (Raju, 2003). While in eight-spored N. crassa, the situation is a bit different and which is ex pected, as it is eight-spored as compared to the four-spored species. In N. crassa, the ascospore pairs are aligned themselves in linear fashion and exhibit genetic events during the process of meiosis. The process of crossover, which occurs at the four-strand distributor point during the meiotic division, becomes visually obvious. In N. crassa, the segregation of alleles during meiotic division is not fixed but it varies depending upon the relation between the gene marker and the centromer

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