Biology Practical 2 - Lab 2 PDF

Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 2 Kingdome of Protista The Kingdom Protista, also known as the Protist Kingdom, is a biological kingdom that includes a diverse group of eukaryotic organisms that do not fit into any of...

Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 2 Kingdome of Protista The Kingdom Protista, also known as the Protist Kingdom, is a biological kingdom that includes a diverse group of eukaryotic organisms that do not fit into any of the other kingdoms of life. Protists are unicellular or multicellular organisms that are typically found in aquatic environments, but can also be found in soil, on the surface of other organisms, and even in the air. They exhibit a wide range of nutritional modes, including autotrophic, heterotrophic, and mixotrophic, and have varied structures and characteristics. Some examples of protists include algae, amoebas, ciliates, and slime molds. Protists play important roles in various ecosystems, serving as primary producers, decomposers, and food sources for other organisms. Types of Protista Protists are a diverse group of eukaryotic organisms that include unicellular, colonial, and multicellular forms. There are several different types of protists, including: 1. Algae: Algae are photosynthetic protists that can be unicellular or multicellular. They are found in both freshwater and marine environments, and they play an important role in 1 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 2 primary production in aquatic ecosystems. Examples of algae include diatoms, dinoflagellates, and green algae. 2. Protozoa: Protozoa are unicellular protists that are heterotrophic, meaning they obtain their nutrition by ingesting other organisms. They are found in a variety of environments, including soil, freshwater, and marine environments. Examples of protozoa include amoebas, ciliates, and flagellates. 3. Slime molds: Slime molds are unicellular or multicellular protists that feed on bacteria, fungi, and other organic matter. They are typically found in soil, decaying vegetation, and other moist environments. Slime molds can form complex structures during their life cycle, such as fruiting bodies. 4. Water molds: Water molds are fungus-like protists that live in aquatic environments. They are known for causing disease in plants and animals, including the Irish potato famine. Protozoa Protozoans are unicellular organisms. Historically, protozoans were called “animal” protists as they are heterotrophic and showed animal-like behaviors. There are also parasitic protozoans which live in the cells of larger organisms. Most of the members do not have a predefined shape. For instance, an amoeba can change its shape indefinitely but a paramecium has a definite slipper-like shape. The most well-known examples of protozoans are amoeba, paramecium, and euglena. Unlike other members of this group, euglena is a free-living protozoan that has chlorophyll, which means it can make its own food. 2 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 2 The protozoans can be divided into four major groups: Amoeboid protozoans: Mostly found in water bodies, either fresh or saline. They have pseudopodia (false feet) which help to change their shape and to capture and engulf food. E.g. Amoeba. Flagellated protozoans: the members of this group have flagella. They can be free-living as well as parasitic. E.g. Euglena. Ciliated protozoans: They have cilia all over their body which help in locomotion as well as nutrition. They are always aquatic. E.g. Paramecium. Slime Molds Slime molds are saprophytic organisms (they feed on dead and decaying matter). These are tiny organisms that have many nuclei. Usually, Slime molds are characterized by the presence of aggregates called plasmodium and are even visible to the naked eye. 3 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 2 Algae Algae are photosynthetic protists that can be unicellular, colonial, or multicellular. They are found in both freshwater and marine environments and can be a significant component of plankton in aquatic ecosystems. Algae are unique among protists in that they contain chloroplasts, which are organelles that contain chlorophyll and other pigments used for photosynthesis. The ability of algae to photosynthesize makes them an important primary producer in aquatic ecosystems, producing oxygen and organic compounds that form the basis of the food chain. Algae are classified based on their pigments and cell wall composition. For example, green algae contain chlorophyll a and b, and their cell walls are composed of cellulose. Red algae contain chlorophyll a and phycobiliproteins, and their cell walls are composed of complex polysaccharides. Brown algae contain chlorophyll a and c, and their cell walls are composed of cellulose and alginic acid. Algae are important for human use and consumption, as they are used in food products, supplements, and industrial processes. For example, some species of algae are used as a source of omega-3 fatty acids, while others are used in the production of agar, a gelatinous substance used in the food industry. Harmful of Protista Some protists can be harmful to humans, animals, and the environment. Here are some examples: 4 Biology practical 2 First class, Second semester Asst. Lec. Dunya.A.Mohammed Lab 2 Parasitic protists: Some protists, such as Plasmodium, Trypanosoma, and Giardia, are parasitic and can cause diseases in humans and animals. Malaria, sleeping sickness, and giardiasis are some of the diseases caused by parasitic protists. Harmful algal blooms (HABs): Certain species of algae can undergo rapid and massive growth, leading to what is known as a harmful algal bloom. These blooms can produce toxins that can kill fish and other aquatic organisms, contaminate seafood, and cause respiratory problems in humans. Red tide: A type of HAB caused by dinoflagellates, red tide can produce toxins that can accumulate in shellfish and cause paralytic shellfish poisoning in humans who consume them. Environmental disturbances: Some protists, such as water molds, can cause environmental disturbances, such as the die-off of fish and other aquatic organisms. 5