lab 3 Semaster2.pdf

Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 3 Fungi kingdom (yeasts and molds) The Fungi Kingdom, also known as the kingdom Fungi, is one of the five major kingdoms of living organisms. Fungi are eukaryotic organisms, which means they have...

Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 3 Fungi kingdom (yeasts and molds) The Fungi Kingdom, also known as the kingdom Fungi, is one of the five major kingdoms of living organisms. Fungi are eukaryotic organisms, which means they have a true nucleus and other membrane-bound organelles in their cells. Fungi can be found in many different environments, including soil, water, and on living and dead organisms. They play important roles in many ecosystems, as decomposers that break down dead organic matter, as mutualists that form symbiotic relationships with other organisms, and as pathogens that can cause diseases in plants, animals, and humans. The Fungi Kingdom includes a diverse range of organisms, including mushrooms, yeasts, and molds. Fungi are distinct from plants and animals in many ways, including their method of obtaining nutrients (by absorption rather than photosynthesis or ingestion) and their unique cell walls made of chitin rather than cellulose. Structure of fungi The structure of fungi can vary greatly depending on the species and the stage of its life cycle. However, there are some common features that can be found in most fungi: 1 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 3 1. Hyphae: These are the long, branching filaments that make up the body of the fungus. They grow and extend through their environment, allowing the fungus to absorb nutrients from its surroundings. 2. Mycelium: This is the mass of interconnected hyphae that makes up the body of the fungus. It can grow to be quite large and can spread out over a large area in search of nutrients. 3. Spores: These are the reproductive structures of the fungus. They are usually produced at the tips of specialized hyphae, called sporangiophores, and are released into the air or water to begin a new fungal colony. 4. Cell wall: The cell wall of fungi is made up of chitin, a tough, flexible polysaccharide that provides structural support and protection. 5. Cytoplasm and organelles: Fungal cells contain a variety of organelles, including a nucleus, mitochondria, ribosomes, and endoplasmic reticulum, which are involved in various cellular functions such as metabolism, energy production, and protein synthesis. 6. Reproductive structures: Some fungi, such as mushrooms and puffballs, produce elaborate reproductive structures that are often visible to the naked eye. These structures can be used to identify different species of fungi. Benefits of fungi Fungi play many important roles in the natural world, and there are many benefits of fungi to humans, animals, and the environment. Here are a few examples: Decomposition: Fungi are important decomposers that break down dead organic matter, such as leaves, wood, and animal carcasses, and recycle nutrients back into the ecosystem. This helps to maintain soil fertility and nutrient cycling in forests, grasslands, and other ecosystems. 2 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 3 Food: Many types of fungi are edible and are used as a food source for humans and animals. Examples include mushrooms, truffles, and morels, which are highly valued for their unique flavors and nutritional content. Medicine: Fungi produce a wide range of bioactive compounds, including antibiotics, immunosuppressants, and anticancer agents, which have been used to treat human diseases. For example, penicillin, one of the first antibiotics, was discovered from a fungus. Bioremediation: Fungi can be used to break down pollutants and toxins in the environment, a process called bioremediation. They are especially effective at breaking down complex organic molecules, such as polycyclic aromatic hydrocarbons (PAHs) and chlorinated solvents, which can be difficult to remove through other means. Agriculture: Fungi can form symbiotic relationships with plants, such as mycorrhizae, which help plants to absorb nutrients from the soil and improve their growth and health. They are also used in the production of fermented foods and beverages, such as cheese, beer, and bread. Overall, fungi are a vital part of the ecosystem and provide many benefits to humans and the environment. Harmful of fungi While there are many benefits of fungi, some types of fungi can also be harmful to humans, animals, and the environment. Here are a few examples: Pathogens: Some fungi can cause diseases in plants, animals, and humans. For example, the fungi that cause ringworm, athlete's foot, and thrush are common fungal pathogens in humans. 3 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 3 Allergens: Some people are allergic to certain types of fungi, such as mold spores, which can cause respiratory problems and allergic reactions. Toxins: Certain species of fungi produce toxins, such as mycotoxins, which can be harmful to humans and animals if ingested or inhaled. Mycotoxins can be found in contaminated food and feed, and can cause liver damage, cancer, and other health problems. Plant diseases: Fungal diseases can also affect crops, causing yield losses and reducing the quality of agricultural products. Here are a few examples of harmful fungi: Aspergillus: Aspergillus is a genus of molds that can produce mycotoxins, such as aflatoxins, which are carcinogenic and can cause liver damage and other health problems in humans and animals. Aspergillus can also cause aspergillosis, a fungal infection that can affect the lungs and other organs. Candida: Candida is a genus of yeasts that can cause candidiasis, a fungal infection that can affect the skin, mouth, and other mucous membranes. Candidiasis is most common in people with weakened immune systems, but can also affect healthy individuals. Fusarium: Fusarium is a genus of fungi that can produce mycotoxins and cause disease in plants and animals. Fusarium infections can cause a wide range of symptoms, including skin lesions, eye infections, and respiratory problems. Rhizopus: Rhizopus is a genus of molds that can cause mucormycosis, a serious fungal infection that can affect the sinuses, lungs, and other organs. Mucormycosis is most common in people with weakened immune systems, but can also affect healthy individuals. 4 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 3 stain of fungi Staining is a technique that is commonly used to enhance the visibility of fungi under a microscope. Here is a general procedure for staining fungi: 1. Prepare a fungal sample by fixing it onto a microscope slide. This can be done by air- drying a drop of the sample onto the slide or by using a fixative, such as formalin or ethanol. 2. Choose a suitable stain for the type of fungi you are observing. Common stains for fungi include lactophenol cotton blue, potassium hydroxide (KOH), and periodic acid-Schiff (PAS) stain. 3. Apply the stain to the fungal sample. This can be done by adding a drop of the stain to the sample on the microscope slide and allowing it to soak in for a few minutes. 4. Rinse the stain off the slide using a gentle stream of water or another suitable solution, such as methanol. 5. Dry the slide by gently blotting it with a paper towel or allowing it to air-dry. 6. Observe the stained fungal sample under a microscope, using appropriate magnification and lighting settings to enhance visibility. 7. When stained, fungi can be observed with greater contrast and detail under a microscope, making it easier to identify different structures and features. For example, lactophenol cotton blue stain can be used to highlight the chitin in the fungal cell walls, while PAS stain can be used to detect the presence of fungal polysaccharides. 5