 Assalamu alaikum. In today's lecture, we are going to talk about LG and Fungi. LG and Fungi are two of the most important parts of the ecosystems of the world. Both are very abundant living organisms present on planet Earth and makes a very important part of biosphere. We will talk about LG and Fungi one by one. First of all, we talk about LG. LG, single is LG, singular, LG and plural LG. These are the living organisms which are one of the most important group of producers on Earth because these organisms are photosynthetic. They convert inorganic carbon to organic carbon using sunlight as the energy source. LG are the organisms which ranges in size from unicellular microscopic to very large seaweeds which ranges up to about 100 meters in length in their height. So, there is a wide variety of the group of organisms, the living organisms called LG present on the planet Earth. LG are the most important producers of the biosphere. Producers mean that they are autotrophic and they produce their own food utilizing the sunlight as energy source and carbon dioxide that is inorganic carbon as the carbon source and produces the chemical form of energy ATP for themselves and carbohydrates for themselves as food and for other organisms as well. LG provide food for various organisms in the food webs and the food chains in all the ecosystems, particularly the water ecosystems. In lakes, in oceans, in ponds, LGs makes the most important part of the producers because all the other organisms which are consumers include the animal like protists, the small animals, herbivore, fish, they all depend for their food on LG. They are dependent upon LG for their organic food source because these are the heterotroph. They have to take their energy in the form of organic carbon molecules from some producers. LG utilizes carbon dioxide and they are the most important producers of the oxygen because we know they are photosynthetic, they utilize carbon dioxide and they produce oxygen. So, they are the most important contributors of oxygen to the environment, planet earth and we know that oxygen is necessary for the living beings, for human beings, for animals because they use oxygen in their respiration and without oxygen there is no life which could survive. Secondly, they utilize carbon dioxide. We know that carbon dioxide is one of the most important gases which causes the greenhouse effect, that is increase in the temperature of the earth and because these organisms utilize carbon dioxide they actually reduces the greenhouse effect. LG, LG are the source of various foods and other materials for other living beings including the human beings. For example, LG, from LG we produce many cosmetics from many algal products, certain ice creams are also produced. From LG gelatin like materials are obtained. So, LG are utilized in so many things and on top of the list we can make certain fuels ethanol from LG because we know that the world is fishing fuel shortage and this shortage is going to increase in coming years. So, LG are very important source of biofuels. Biofuels means that the fuels which are obtained from living organisms. LG thrived on earth from the last 1.5 billion years and they are widely spread it all over the planet earth. Now, we talk about the distinguishing characteristics of LG. Number one, they are photosynthetic. LG carry out photosynthesis, utilizes sunlight as energy source, convert in organic carbon into organic carbon as the food source and it means that they are the autotrophic organisms. They are producers, we call them autotroph, autoself, trough food, they feed themselves, they produce their own food. Secondly, LG are eukaryotic organisms. They have a true nucleus. We know that organisms are of two kinds, they consist of two kinds of cells, prokaryotic and eukaryotic. The prokaryotic who do not have a true nucleus that is their nucleus is actually not surrounded by a nuclear membrane and the eukaryotic who have a true nucleus that is their nucleus is surrounded by a nuclear membrane. LG are eukaryotic, they are eukaryotic organisms. Sizes of LG, their size ranges from microscopic unicellular LG, very, very large seaweeds, the length of which or we can say the height of which reaches up to 100 meters. LG, how can we classify LG? We can classify LG based upon their energy storage products, based upon their cell wall structure, based upon their pigments that they produce, so we can classify LG in various ways. Importantly, LG have a cell wall. We know that animal cells do not have a cell wall, prokaryotic cells do have a cell wall, plant cells also do have a cell wall. LG also have cell wall and their cell wall matches more in its structure with the plants. Its cell wall consist of mainly the material called cellulose. This is the same material with which the cell walls of the plants are produced. Now, we have a look that how can we classify LG into various groups commonly? LG, they are classified broadly many times or most of the times based upon the pigments that they produce. LG produces different types of pigments due to which they appear in different beautiful colors. We know some major ones, the green LG, the red LG, the brown LG, golden brown LG and the euclenides. LG also have certain important characteristics. They reproduce both by asexual and sexual means. By asexual means, they normally reproduce by the help of the process called mitosis because we know they are eukaryotic organisms and when eukaryotic organisms divide, they divide by the process of mitosis which is actually division of their nucleus. So, asexually they reproduce by mitosis. Sexual reproduction in LG though takes place, but it takes place only during the environmental stress. Normally, they reproduce that is, they produce their young ones with the help of mitosis that is cell division, simple cell division. But whenever there is an environmental stress, they need to make spores for some time to tolerate that harsh environment or which is we can say intolerable environment for some time. They produce two types of gametes which are named as plus gametes and minus gametes. These gametes fuse to form the zygospore. Zygospore remains there in this form which is actually more protected from the environmental conditions until better conditions come. When the environmental conditions they become favorable, then meiosis occur in the zygospore and it give rise to again the haploid that is n number of chromosomes in the zygospore's products that is the cells and each cell then give rise to unicellular algae aura, multicellular colony. Let us have a look on a unicellular algae, the top one and on the other side you can observe collunial algae. The top one is called euglina which is very common in most of the ponds, pond waters and the other one is wall walks. You can observe a large colony and daughter colonies present inside that wall walks organism, the larger colony, the parent colony we can say. When these colonies grow, then they separate from the parent colony and give rise to a newer colony. So algae are unicellular that is they can stay as a single cell and they can stay in colonies, groups or aggregates of organisms. Now we talk about different types of algae and their characteristics. We know that algae are widely characterized or widely grouped or classified based upon the pigments that they produce. Agi produces green pigments, they produces red pigments, brown pigments, goldish brown pigments. We call them green algae if they produces the green pigments, very common pigments chlorophyll, chlorophyll A and chlorophyll B. These are the same pigments which are produced by the plants. Algae also have the same pigments chlorophyll A and chlorophyll B. So some scientists assume that the land plants which have the same pigments as algae they may have a risen from these green algae which also have same type of cell wall as the higher plants do have. The green plants do have the land plants and they also have both types of chlorophylls that is chlorophyll A and chlorophyll B and both the algae in the land plants. They also carry out photosynthesis, they are producers, they are autotrophic organisms that is they make their own food. So there are many characteristics match. Green algae are amongst the most widely distributed algae on earth. There are about 7000 species of green algae present on earth. We can see on various the surface of various pounds and surface of various lakes very large huge scum that is layer on the surface covered by the covering the top of top layer of the water which is green in color that is actually the green algae and it provides food for all the food webs and food chains in the water body maybe lake maybe pound maybe sea or an ocean. Green algae are the source of different types of products. Sometimes a bigger mass of algae could be converted for making or we can say some products could be extracted out of larger masses of green algae, some cosmetic products, some gelatin like materials which are used in certain different types of foods. Green algae also have very very important role in reducing the greenhouse effect. Now we know that the greenhouse effect means that the temperature of the earth is rising due to presence of certain gases in the atmosphere. A carbon dioxide is one of the important gases which are involved in the greenhouse effect. Algae can help a lot in reducing the greenhouse effect by reducing the carbon dioxide in the environment. It is said that about two tons of algae can utilize about one ton of carbon dioxide and convert it into oxygen. So and secondly this large algal biomass have another benefit we can convert it into fuels by various methods we can convert it into alcohols ethanol and we know that ethanol the alcohols they are one of the most important forms of the biofuels we can also convert this algal biomass into biodiesel. So green algae is one of the most important algae group of algae which are widely distributed which are present almost in every part of the world and they are very very useful as part of the ecosystem and they can reduce the greenhouse effect they can produce more oxygen reduce carbon dioxide and they could be used to extract the biofuels. Now we talk about other kinds of algae red algae are also very widely distributed form of algae there are about 4000 species of red algae present in the world they have specific type of pigment called phycobilane which give them a red color this pigment is water soluble most of the other algal pigments they are not water soluble and they could be dissolved or we can say mixed up only with organic solvents that is alcohol and acetone etc. With the red pigment phycobilanes they are soluble in water as water these gives red color to these alga. Red algae are mainly present in oceans and seas that is the large huge water bodies and these alga are used to produce many cosmetic products lot many cosmetics products are extracted from these red algae's. Red algae's are also source of one more very important material gelatin like material we know that when we have to solidify certain foods like in the form of gels jellies we can say we have to make jellies jelly like materials we need to some agent that help in making those gels that is converting material into jelly like materials initially an animal based material that is a material extracted from animals named gelatin was used for doing this process but we know gelatin have very high fatty fat content and this is not good for health and some people also do not like to use animal like animal based products for those people these gelatin like materials from red algae are used in making all the jelly like food materials and other related materials. Now we talk about the brown algae brown algae have about 1500 species they include the very very large huge sea weeds and other weeds their height their length sometimes reaches about 100 meters they are that long they are also mostly present in seas or oceans they are mainly marine they have different kinds of pigments which give them a brownish color these are very very important for the scientific community because from these sea weeds particularly we extract a very important material called agar or sometimes called agar agar this material is extremely important because this is used to culture the microorganisms whenever we need to culture microorganisms on a solid surface we provide them with certain nutrients but to convert those nutrients which are in a liquid form in a solid form that is making them converting them into a gel like form we need to use agar agar is a product of sea weeds it is extracted from sea weeds so and before using agar all the other materials which were used to solidify the microbiological media in which that is media or we can say nutrient media in which we can culture microorganisms like bacteria and the and some other microorganisms these materials were very costly like gelatin sometimes starch these materials were number one very costly and number two they were very difficult to use discovery of agar was one of the revolutionary say steps in the history of microbiology so microorganisms are normally cultured on a solid surface medium which is actually solidified with the help of material called agar which is extracted from the sea weeds then we talk about the golden brown algae golden brown algae are comparatively less widely distributed they are present in marine environments that is in oceans and these algae are used to make some petroleum products for you for making some petroleum products golden brown algae can help us then comes the euglinoids we know commonly a very common microorganism of a pound euglina if we get a sample from pond water and observe it under the microscope we usually find out certain small microorganisms which are moving very fast and have some green colored material inside them these are the euglina euglinoids euglinoid those euglinoid group have many other microorganism that is microscopic unicellular algae these are have sometimes animal like properties and sometimes they have some plant like properties so euglinoids are a parts of pound ecosystems that is mostly the freshwater ecosystems or the lake ecosystems euglinoids are the producers of freshwater ecosystems mostly that is they carry out photosynthesis and they provide a source of food for the animal like microorganisms of the pound or the lake and hence they help in the food chain or we can say they make the start or beginning of the food chain in fresh waters.