Introduction To Biodiversity PDF

Introduction To Biodiversity  Biodiversity is defined as the variation of living forms on earth which includes plants , animals ,microorganisms , contains genes Biodiversity and form the complex ecosystem. Total number of biod...

Introduction To Biodiversity  Biodiversity is defined as the variation of living forms on earth which includes plants , animals ,microorganisms , contains genes Biodiversity and form the complex ecosystem. Total number of biodiversity : 13 million Identified biodiversity : 1.75 million  By protecting biodiversity ,we are able find new source of food and drink. A significant proportion of drugs is derived directly or indirectly from biological sources. A wide range of industrial materials like dyes , fibers , resins etc. are derived directly from biological sources. Benefits of The natural beauty provided by biodiversity inspired composers, artists, and poets. Biodiversity Ecosystem and ecological process plays an important role in breakdown an absorption of pollutants Biological diversity helps in formation and maintenance of soil texture and the preservation of moisture and nutrients. Natural pesticides using biodiversity are in many ways superior to their artificial chemical pesticides. Biodiversity also has great importance as a direct source of income and economic development.  Tourism Scientific research and investigation Scope of Medicine Biodiversity Agricultural production Balance of ecosystem  The kingdom Protista includes all unicellular and eukaryotic organisms such as protistan algae (Euglena , diatoms) , slime moulds and protozoans.The organism included in this kingdom shows following characteristics. They are mostly aquatic , unicellular and eukaryotic organisms. They consist of membrane bound cell organelles like mitochondria. Kingdom: Plastid , endoplasmic reticulum etc. They contain double stranded helical DNA in the Protista nucleus and organized into distinct nucleus enclosed by the nuclear membrane. Cell wall , if present ,contains cellulose. They possess diverse modes of nutrition , viz ,photosynthetic , saprotrophic , parasitic , holozoic etc..  The organisms mostly form planktons. The photosynthetic plants are called phytoplanktons which form an important group of producers in aquatic medium. They also possess cell wall. The non-photosynthetic organisms are called zooplanktons which have holozoic nutriti on.They do not possess cell wall. They reproduce by both sexual and a sexual methods. Their development don't include embryo These organisms do not show much cellular differentiation ; hence ,tissue system is , absent  Protozoa are microscopic and acellular animals. They are without tissues and organs. They are solitary or colonial in habit. They consist of one or more nuclei. Protozoans have following general characters : Usually microscopic animals which are difficult PROTOZOA to see by naked eye. Body is unicellular with one or more nuclei. Body is naked or provided with pellicle and some bear simple to complex shell or exoskeleton. They are solitary or colonial  The single cell can perform all bodily activities. Nutrition isoholozoic , holophytic , saprozoic or parasitic. Locomotory organelles are either pseudopodia or flagella or cilia or absent. Characteristic Reproduction in generally by fission (binary or of Protozoa multiple) , budding , conjugation or syngamy. Respiration through general body surface or contractile vacuoles in some They may be free-living or parasitic or commensal.  Protozoa Phylum—Protozoa. (Gr. Protos = first ; zoon=animal) The phylum includes the simple, primitive microscopic and unicellular animals. But they can perform all the physiological functions like digestion, extraction, reproduction etc. quite effectively like a multicellular animal. Characters of Protozoa These are microscopic ,unicellular animals showing protoplasmic grade of organization. They are free-living in fresh-water, marine or live in damp soil. Some are parasites. Protoplasm differentiated into outer ectoplasm and inner endoplasm. A distinct nucleus but occasionally many nuclei are present. Locomotion takes place by pseudopodia or cilia or flagella or by contraction of myoneme fibrils. Respiration by diffusion. Nutrition may be holozoic ,holophytic , saprophytic or parasitic. Excretion takes place by general body surface and to some extent by contractile vacuoles. Reproduction, asexually by budding, binary fission or multiple fission and sexually by conjugation or by gamete formation. Encystment takes place to overcome unfavourable circumstances.  The basis of classification is the locomotory organelles. Class: Rhizopoda (Locomotion by pseudopodia ) Pseudopodia are the chief organelles of locomotion and food capturing. Most of them are free-living. Some are parasitic. Body is naked. Example: Amoeba, Entamoeba  Class: Ciliata Cilia are the chief organelles of locomotion and food capturing. The body is covered with the thick pellicle. Mostly free living some are parasitic. Morphologically two different type of nucleus are present. Fresh water forms have one or more contractile vacuole. Reproduction mainly occurs transverse binary fission and conjugation. Example: Paramecium, Vorticella  Class: Flagellata Flagella are chief organelles of locomotion and food capturing. Their body is covered with thick pellicle. They are free living and parasitic. Only one nucleus is present. Fresh water forms have one or more contractile vacuole. Reproduction mainly occurs by binary fission. Example: Euglena, Leishmania  Class: Sporozoa Locomotory organelles absent. The body is covered with the pellicle. They are exclusively parasitic. Spores usually present. Reproduction mainly by multiple fission. Example: Plasmodium, Monocystis WELCOME BACK STUDENTS! Malarial Parasite There are four types of Plasmodium which cause different types of Malaria. They are: Plasmodium vivax: This cause benign fever. The fever occurs after every 48 hours or on every third day. Plasmodium malaria: This cause quartan fever. The fever occurs after every 72 hours or on every fourth day. Plasmodium falciparum: This is responsible for the fatal malaria which is also called malignant malaria or aestivo-autumnal malaria. Fever occurs irregularly and as such it is very difficult to prescribe any medicine for this malaria and so the patient dies. Plasmodium ovale: It causes mild or ovale malaria. In this case fever occurs after every 48 hours. Life cycle Life cycle To complete the life cycle Plasmodium requires two hosts. Man is the secondary host and female Anopheles is the primary host. As it requires two hosts to complete its lifecycle it is a digenetic parasite. The life-cycle in man is asexual and is called Schizogony. The cycle in female Anopheles is sexual and is known as sporogony  Life-cycle in Man Transmisson: A healthy man is infected with infective stage of the parasite called sporozoite. It is a minute sickle shaped structure found in the salivary glands of female mosquito. When a mosquito bites a healthy man these sporozoites enter the blood with saliva of the mosquito. As Life Cycle these are transmitted during bite the mode of transference is called inoculative transference. The life cycle of men is divided into three major cycles- 1) Pre-erythrocytic cycle 2) Exo-erythrocytic cycle 3) Erythrocytic cycle  Pre-erythrocytic cycle The sporozoites which enter the liver cells feed in glycogen of the liver and enlarge into a large round adult structure called cryptozoite. The cryptozoite Major Cycles by multiple fission forms about 1000 small elongated structure called cryptomerozoites. These break the cryptozoite and liver wall to enter small liver sinusoids. Some of them enter new liver cells to start exo-erythrocytic cycle and some may enter RBC to start RBC cycle.  The cryptomerozoites which enter the liver cells mature into large metacryptozoites or phanerozoites. These are of two kinds based on size. I)The large one is macrometacryptozoite which divides to form 64 comparatively Exo- large macrometacryptomerozoites which keep continued the exo-erythrocytic cycle in the liver cells. erythrocytic II) The smaller one is the micrometacryptozoite which also by multiple fission forms about 100-1000- cycle minute micrometacryptomerozoites which leave the liver cells and enter the erythrocytes to start the erythrocytic cycle.The liver cycle is completed within 8-10 days and the time interval between the entry of the parasite in the blood upto the starting of erythrocytic cycle is called pre-patent period (8-10 days).  This is also called "Golgi cycle" as Golgi discovered the cycle. I)The micrometacryptomerozoites which attack RBC feedson protein(amino acids) of haemoglobin present present in th RBC and becomes larger and almost round. This is the trophozoite or vegetative stage of parasite. As this is the feeling stage it is also called nutritive stage. II) Then appears a large vacuole in it and the nucleus is pushed at Erythrocytic one end. It looks like a ring and the stage is called signet ring stage. III) Then the vacuole disappears, and it becomes amoeboid in Cycle shape and shows amoeboid movement. This stage is amoeboid stage. IV)Slowly it enlarges in size with the enlargement of thr RBC and almost completely fills the RBC. This is known as Schizont Stage. The nucleus of the schizont divides into 12-24 nuclei, each of which gets covered by a bit of protoplasam and forms erythrocytic merozoite which arrange at the periphery of the schizont in circles. At the center of the schizont accumulate a poisonous substance (toxic) called haemozoin which is the byproduct of hemoglobin. In the RBC appears few dot-like structures called Schuffner's Dot V) RBC enlarges and bursts liberating merozoites and haemozoin in the blood. Due to mixing of haemozoin in the blood, the man develops fever. Muscular pain, loss of appetite. These are the symptoms of malaria fever. The erythroritic cycle takes 48 hours to complete. The merozoites now enter new RBC and continue the cycle. The period between entry of sporozite in man upto the appearance of first symptom of malaria is known as incubation period (10-17 days average 15 days) The merozoites after several repeated erythrocytic cycle undego certain adaptaions.After entering the RBC the leave the blood circulatiob and reach the bone marrow where they become round with centrally placed nucleus. These are microgametocytes. Some become oval with eccentrically placed nucleus called megagametocytes. These than migrate to the general circulation and do not undergo further devlopment until they reach the stomach of the female Anopheles. They require low temperature for further development. Life cycle in female Anopheles The mature gametocytes along with different stages of malarial parasite are present in the blood of the infected man. When a female Anopheles bites such an these enter the stomach of the mosquito and the life cycle is continued toward completion by four process namely gametogenesis, fertilization, oocyst formation and sporogony. Gametogenesis I) formation of microgamets: The nucleus of the microgamet ocyte divides to form 4-8 nuclei, the first division is meiosis. The nuclei arrange at the periphery and equal number of projections are given out. One nucleus migrates in one projection. These vibrate and get seprated from the remainder protoplasam of the microgametocyte. This process is called exflagellation which takes place in the lumen of the stomach. The elongated structures are called microgametes. ii) Formation of megagamete: The megagametocyte also undergoes meiosis. During this process it gives out two polar bodies and forms one oval elongated megagamete. It develops a projection called fertilization cone or cone of reception. Fertilization: One of the microgamate fuses with one megagamete to form Zygote. Oocyst Stage: It was formerly believed that the zygote becomes elongated and becomes ookinete which penetrate the stomach wall to form oocyst. But in 1960 Howard discovered that the zygotes which penetrate the stomach membrane and become encysted to form oocyst. The zygote which cannot penetrate the stomach wall become elongated to form Ookinete which are expelled out with faecal matter. Sporogony: The nucleus of the oocyst divides repeatedly to form many nuclei. Each nucleus becomes surrounded by a bit of protoplasm to form Cytoplasmic masses or sporoblast. Again, the nucleus of the sporoblast, divides repeatedly and each nucleus gets covered by a bit of the protoplasm to form the sickle shaped sporozoites. The oocyst now bursts and sporozoites are set free in the body cavity of the mosquito. From there they migrate to the salivary gland and are stored there for reinfection. Control of malaria Control of malaria is national problem. Government has established malaria eradication department to check and control malaria. Generally, malaria can be recovered by the following methods: Destruction of mosquitoes: Mosquitoes carry the malarial parasites and transmit them from one man to another during bite. So, to control malaria it is essential to destroy mosquitoes. This can be done by the following methods. I) Spray D.D.T flit or other insecticides in open drains, ditches so that eggs larvae and pupae are destroyed. ii) By spraying kerosene oil eggs, larvae and pupae can be killed. Larvae and pupae die due to blockage of respiratory openings by oil. iii) Mosquitoes can be controlled by filling up the small ditches, holes etc. By earth so that they cannot lay eggs. Iv) Mosquitoes can be killed by hands, traps and by fumigation. The fumes of Sulphur, Cersol and camphor can drive or even kill mosquitoes in a room. V) By introducing fishes like Gambusia, Clarias (magur), Heteropneustes (singhi) Channa (gorai) etc. In pond which feed on egg, larva and pupa of mosquito. This type of control of one animal by another is called biological control. Insectivorous plants like Utricularia (bladderwort) can also kill larvae and pupae of mosquitoes. Prevention from infection For this it is essential to save oneself from mosquito bite by the following methods: I) Use of mosquito-net during sleep. II) One should use mustard oil or mosquito repellent cream on exposed body surface during night. III) Use of medicine if one lives in a place where often malaria occurs. Use of proper medicines The well-known medicine is quinine which is prepared from the bark of cinchona tree. This kills the different stages of Plasmodium but is ineffective to gametocytes. There is another medicine plasmochin which is effective to gametocytes. It has been found that paludrine is the best medicine as it is effective to all the stages of malarial parasite. Malaria cannot be controlled by vaccination as Plasmodium cannot produce antibodies in human blood which is an essential feature of vaccination. 10/12/2020 THURSDAY Second Example Of Phylum Protozoa: Paramecium Phylum- Protozoa Class- Ciliata Genus- Paramecium Species- P. caudatum Habit and habitat P. Caudatum is common fresh-water ciliata found on the water surface of the ponds, ditenes and stagnant waters rich in organic nutrients (oligosaphrobic). It is free-living and can be cultured in the laboratory by placing a little pond water on a petridish containing boiled hay, wheat and water at room temperature. Structure Paramecium caudatum resembles a slipper and so commonly called "slipper animalcule". The size of the Paramecium is variable, ranging from 0.06 mm to 0.3 mm long. The anterior end is broad and rounded while the posterior end id more of less pointed. The upper dorsal surface is convex while the ventral concave surface bears the mouth and is also called Oral Surface. The cytoplasm of the body is divided into an outer, narrow cortical zone or ectoplasm and inner medullary region or endoplasm. The ectoplasm is protective in nature, the outermost layer which is secreted by ectoplasm forms the colorless, elastic, cuticular pellicle. It helps to maintain the shape of the body. Under higher magnification of microscope, the pellicle is found to be composed of hexagonal areas from the center of each of which comes out a small cilium. Each cilium has central axoneme formed by axoneme formed by fibrils surrounded by protoplasm. Structure The entire body of Paramecium is covered by cilia of almost equal size. Below the pellicle is found round basal granules from which a cilium originates and comes out through the center of hexagonal areas. The basal granules are connected by fine fibers like contractile structure called kinetodesma forming the so called neuromotor system or infra- ciliary system. The cilia are responsible for locomotion and ingestion while the coordinated movement of cilia is controlled by Infra-ciliary. There is a group of large cilia at the posterior end forming caudal tuft. Structure In between two cilia, is an opening of trichocyst. It is a spindle shaped body arranged in a row at right angle to the pellicle. Each trichocyst is made up of a pointed spike and a swollen part containing fluid. When irritated, trichocyst discharges long adhesive threads. It was considered to be defensive organelle but now it is considered as an organelle of anchorage. The Endoplasm is soft and granular. The protoplasm show streaning movement and contains various cytoplasmic inclusions like reserve food materials (starch, glycogen, fat etc.), food vacuoles, contractile vacuoles and nuclei. Structure Food vacuoles containing food materials are of varying size and are non-contractile in nature. They move about in the endoplasm by streaming movement of protoplasm. The nuclear apparatus of Paramaceium shows dimrophic nature. There is a large kidney shaped meganucleus. It has no nuclear membrane and contains tropochromatin. It is concerned with ordinary life processes except reproduction and so is also called vegetative nucleus. The other one is small, round with nuclear membrane containing idiochromatin and is associated with reproduction. So, it is called reproductive nucleus. Reproduction Paramecium reproduces asexually by transverse binary fission by conjugation. Binary fission: During favorable conditions of life binary fission takes place in the following way- I) The micronucleus divides mitotically, and the resulting two daughter micronuclei go to opposite ends of the cell. II) The meganucleus divides amitotically. It becomes elongated and divides by a constriction in the middles. III) At the same time a constriction appears transversely in the middle of the body which deepens, and the body is divided into two halves, each with a mega and a 'nicronucleus'. New parts if necessary are developed in the daughter paramecium before separation and the two grow to full size. It can go binary fission 2-4 times/day. Conjugation Conjugation. After several repeated binary fission, the animal loses its vigour and it cannot divide by binary fission. This is shown by lower nucleo-cytoplasmic ratio (N/C ratio). It is said that lower N/C ratio is an indication of lower activity and consequent lower rate of energy production. So, to gain energy the animal must undergo nuclear reorganization to gain energy which is indicated by higher N/C ratio. This done by the method called conjugation. There are other authorities who are of the opinion that the shortage of food, certain chemicals secreted by Paramecium, certain range of temperature and light may also instinct the animal to conjugate. It is certain that it never takes place among the descendants of a single individual (one clone) but always between two individuals of two different stains forming two different clones.  Thus, there is physiological sexual difference but absence of any morphological sexual difference. The whole process takes place in the following manner. A) Two paramecia come together and attach themselves by the ventral surfaces. They are called conjugants. B) The ectoplasm breaks down the point of the attachment and an endoplasmic bridge is formed between the two animals. C) Certain nuclear changes now take place which is most important part of conjugation. I) Micronucleus of each conjugant moves away from the meganucleus. The meganucleus begins to degenerate breaking up into small fragments which are later absorbed by the cytoplasm. II) Micronucleus of each divides twice, one of the division being meiosis division resulting into four haploid micronuclei. III) Of the 4 micronuclei 3 disappear and the fourth one divides unequally forming one small active male pronucleus and a large inactive female pronucleus. IV) The male pronucleus of one passes through the protoplasmic bridge into the other individual and fuses with the female pronucleus forming a zygote nucleus. But it is better to call this fused nucleus as synkaryon as in this process there was no fusion of two gametes but only of two nuclei. V) Two paramecia now separate and are called exconjugants. The fused nucleus of each divides thrice forming 8 equal sized in each, VI) 4 of these 8 become larger and form macronuclei. Out of the other 4, three disappear and the fourth divides into two. With the division of exconjugant resulting two individuals each having one micronucleus & two meganuclei.  VII) In each such individual, the micronucleus again divides, and this is followed by a fission producing individuals each with one mega- and one micronucleus. D) From each exconjugant, four individuals are formed. Significance I) Increase in number (reproduction)- As at the end of the process, there is increase in number. We can call this process a kind of reproduction. II) Rejuvenation- It means regain of lost power. This is found in each daughter paramaecium as they begin to feed, grow and undergo binary fission if required. This is also indicated by their higher N/C ratio. III) Variations- The hereditary material of male pronucleus of one conjugant passes into the other thus, bringing about certain changes in hereditary materials of the fused nucleus. As this fused nucleus takes part in the formation of four small individuals, the changed characters are also expressed in these individuals bringing about some kind of variations in the offsprings. Plasmodium and Falciparum Plasmodium falciparum is the most virulent species of Plasmodium in human. The name 'falciparum' is derived by Welch from 'flax' meaning sickle or crescent and 'parere' meaning to bring forth. It is responsible for around 50% of malarial cases. Plasmodium falciparum doesn't have fixed structures but undergoes continuous change during the lifecycle of Plasmodium. Vivax. Humans are the intermediate hosts in which asexual reproduction occurs, and female anopheline mosquitoes are the definitive hosts harbouring the sexual production stage. Infection in human beings with the bite of an infected female Anopheles mosquito. Out of about 460 species of Anopheles mosquito, more than 70 species transmit falciparum malaria. The incubation period is the shortest for Plasmodium Falciparum among plasmodium species. An average incubation period is 10-14 days but may range from 9 to 30 days. Parasites can be detected from blood samples by the 10 day after infection.  Malarial symptom includes similar symptoms like that of plasmodium vivax and Plasmodium falciparum is responsible for all severe human illness and deaths due to malaria. The pathological changes are seen primarily in the spleen, bone marrow, liver, lungs, kidney and brain. It causes malignant tertian or falciparum malaria or pernicious malaria. The term 'pernicious malaria' refers to the series of the phenomenon occurring during and infection. Plasmodium falciparum which, if not effectively treated, threatens the life of patients within 1-3 days. Black water fever is the manifestation of falciparum malaria occurring in previously infected individuals and is characterized by sudden intravascular haemolysis followed by fever and haemoglobinuria. The symptoms are known as black water fever due to dark red to the brown black appearance of urine because urine consists of free haemoglobin.  QUERIES?