the world consists of both the living and the non-living but how do we segregate the two we can do so by looking out for certain characteristics associated with living organisms however these characteristics can be definitive or non definitive one such characteristic is growth living organisms [Music] cellular or unicellular [Music] grow due to cell division however cell division affects these organisms differently in a multicellular organism cell division results in an increase in mass whereas in a unicellular organism like amoeba it leads to the formation of two new organisms interestingly plants grow through cell division throughout their lifespan while animals including humans grow up to a certain age after that cell division occurs only when the body has to replace lost cells in certain tissues however everything that grows cannot be said to be a living organism take the example of a rock that will grow in size if sand gets deposited over it however this growth is external on the contrary growth in living organisms is internal growth is thus a characteristic feature of living organisms non-definitive one reproduction is another important characteristic of living organisms in unicellular organisms and growth are synonymous as both lead to an increase in the number of cells this is not the case with multicellular organisms queer reproduction leads to the creation of an offspring these organisms reproduce either sexually or a sexually sexual reproduction can be seen in higher organisms like man and animals asexual reproduction can be seen in lower organisms through budding has seen in yeast all through fragmentation as observed in flatworm however certain organisms such as sterile worker bees are not capable of reproducing but that doesn't mean they are nonliving reproduction is therefore not a definitive characteristic of the living metabolism is also a characteristic of living organisms we know that organisms are made up of chemicals these chemicals are constantly produced in living beings and converted into biomolecules these conversions are called chemical or metabolic reactions the sum total of all such reactions is known as metabolism it is interesting to note that such chemical reactions can also be imitated in a laboratory however such isolated reactions taking place in vitro are not considered living organisms but are classified as living reactions we can therefore state that metabolism is a definite of feature of living organisms cellular organization is another important characteristic of living organisms is not observed in the nonliving and hence cellular organization is also a definitive feature in all life forms consciousness is another feature associated with living organisms we know that all living organisms sends and respond to environmental stimuli such as light water temperature for instance a sunflower always faces the Sun humans to respond to environmental stimuli and are aware of their surroundings and themselves instance in winters they wear woolens to keep their bodies warm nonliving objects don't respond to external stimuli consciousness is therefore definitive characteristic of a living being say that metabolism cellular organization and consciousness are the three definitive characteristics of living organisms earth is a diverse planet with millions of different types of fungi Lance organisms and animals the range and diversity of living organisms increases as we increase the area of our observation each different kind of plant animal or organism answer species in other words species is a group of similar individuals sharing a common gene pool and interbreeding freely producing fertile progeny today there are about seven to 1.8 million species known to us and this number is ever-increasing as we explore new areas along with the old ones the number and types of living organisms on the earth is referred to as biodiversity it is common to find living organisms being known by different local names in different parts of the world to avoid this confusion the name of a living organism must be standardized [Music] such that it is known by the same name the world over this process is known as nomenclature however to name an organism we need to know it's correct description and to what organism the name is attached to this is known as identification to make the process of identification easier scientists have a sigh scientific or biological name to every known organism the scientific names for plants are based on the principles and criteria given in the International Code for botanical nomenclature or ICBM [Music] for animals in the international code for zoological nomenclature iczn the procedures to assign a scientific to an organism have been agreed upon by scientists and biologists all over the world scientific names help avoid ambiguity as each organism has just one name however certain universal room followed while providing a scientific name to a known organism for example the scientific name for the sacred fig be known as the people tree in India is ficus religiosa here as you can see the scientific name has two components the generic name and the specific epithet ficus represents the genus or the generic name liji Ossa denotes the specific epithet this system of representing a name with two components is called binomial nomenclature and was devised by carolus linnaeus also known as the father of modern taxonomy sometimes the name of the author who first described the species is written at the end of the specific epithet for example Jocelin Lynne is the abbreviated name for Linnaeus moreover scientific or biological names are generally in Latin or derived from Latin irrespective of the origin of the organism also when a scientific name is handwritten both the words and the name are underlined separately whereas when printed it is in italics to indicate its Latin origin finally the first word of the genus starts with a capital letter and the specific epithet starts with a small letter apart from assigning name's - living organisms they must be actually organized for easy study the process of grouping anything into convenient categories based on easily observable characters is known as classification for example plans animals roses flowers and dogs our groups that we can easily recognize each group has specific characteristics and are convenient categories that help us to study organisms the scientific term given for these categories is taxa here each of the groups namely mango trees apple trees neem trees cats and dogs are all taxa however cat is a mammal and all mammals come under animals therefore a cat mammals and animals represent taxa at different levels this process of classifying living organisms into different taxa based on their characteristics is called taxonomy taxonomy isn't new to humans for ages humans have been interested in knowing about different types of organisms and the relationships among them this branch of study is known as systematics means systematic arrangement of organisms however today systematics also includes the identification massification nomenclature as illusionary relationships among organisms therefore in this verse world it is important to classify and named living organisms for their easy identification and study our earth is a habitat of millions of plants and animals and new species are being discovered every day in order to group these plants and animals based on observable characters several taxonomists have classified them in a hierarchical structure that consists of ranks or categories every category is referred to as a unit of classification and is commonly termed as Taksim since the category is a part to the taxonomic arrangement it is known as a taxonomic category and all categories together constitute the taxonomic hierarchy although the classification of living organisms seems difficult you need to have a good knowledge of the characters of an individual organism or a group of organisms to classify them this also helps you identify the similarities and dissimilarities among the same and different kinds of individual organisms organisms are classified using common categories such as kingdom phylum or division Plus order family genus and species these taxonomic categories are also known as broad categories species is the basic rank in a taxonomic category it is a group of individual organisms with fundamental similarities you can distinguish one species from another closely related species based on morphological characters think of the varieties of mangoes available in the market species of rose in the garden rank is genus which consists of a group of related species that exhibit similar characteristics in comparison to species of other genera in case of plants and people trees have certain similarities and therefore belong to the genus ficus animals The Lion the Tyger and the leopard are closely linked are in the genus Panthera however the genus Panthera differs slightly from another genus felis which includes cats the next rank or category is family which consists of a group of related genera with fewer similarities as compared to genus and species example orange lemon and grapefruit belong to the family root AC or the citrus family likewise The Lion the Tyger the and the cat fall into the family felidae although a cat and a dog exhibit some similarities and some differences they are separated into two different families felidae and kanaday respectively order is the next category which is a collection of related families however the similarities is less than that seen in a family for example the order Lepidoptera includes butterflies and moths belonging to the families Napoli on eBay and 10 a day respectively similarly families like Frehley day and Kennedy are included in the order carnivora while plant families like convolvulus II and suelen AC are included in the order poly modules on the basis of floral characters category is plus of related orders consider the two orders promoter and Carnivora Amata includes the monkey the gorilla and the Gibbon while order Carnivora includes animals like the tiger the cat and the dog although these two orders are different they are classified under the class Mammalia phylum or division is the next category animals like fishers Vivienne's child's birds and mammals have common features like the presence of notochord and a dorsal hollow neural system thus categorized as phylum Chordata similarly all flowering plants are categorized under the division angiosperm a or magnolia fighter the highest taxonomic category is Kingdom all animals are put under kingdom Animalia and all plants fall under Kingdom Plantae so as we go higher from species to Kingdom the number of common characters goes on decreasing thus by observing the characteristic features of an individual organism taxonomist s-- have classified living organisms into different taxonomic categories our planet is filled with numerous living organisms to simplify the study of these organisms classified into convenient categories based on their characteristics this classification process is known as taxonomy taxonomic studies require careful identification of the organisms laboratory and field studies are carried out specimens of plant and animal species are collected these studies help in disciplines such as agriculture forestry industry and annoying the biodiversity over the years biologists have developed many methods and techniques that help in taxonomic studies these are also known as economical aids herb areum's Botanical Gardens museums Durer logical parks and keys are some examples of taxonomical AIDS learn a little more about these AIDS a herbarium is a storehouse where a collection of dried plant specimens are mounted on sheets labeled and systematically arranged based on the universally accepted system of classification for use in scientific study details like the date and place of collection the English local and botanical names the family of the disbursements and the collectors name are also recorded these herbarium specimens are often used as reference material in taxonomic studies another place that provides taxonomical aid is a botanical garden a wide variety of plants are cultivated in these gardens for scientific research conservation display and education each plant is labeled with its botanical or scientific name and family some of the famous Botanical Gardens are at Kew in England the indian botanical garden in hora the national botanical Research Institute in Lucknow biological museums set up in educational institutions also act as taxonomical aids these museums have collections of preserved plants and animals which are used for study and reference they are preserved in jars using preservative solutions or as dry specimens insects are collected killed wind and then preserved in insect boxes larger animals are typically stuffed and preserved skeletons are displayed who illogical parks or zoos also help in taxonomical studies these places house wild animals in protected environments similar to their natural habitats under human supervision food habits and behavior can be studied here Kuki is another taxonomical aid used for the identification of plants and animals it is a list of questions that help identify and classify the living organism each question presents contrasting characters of an organism in a pair called a couplet classify the organism the character similar to the organism has to be chosen so in a couplet excepted and the other is rejected questions in this analytical manner helps in identifying the organism separates taxonomic keys are required for each taxonomic category such as family genus and species for the purposes of identification other taxonomical aides like flora manuals and monographs are also used Oh flora is a document that contains information about the plans of a particular country or time manuals provide information that helps in the identification of the names of plant and animal species found in a specific area [Music] is a written account or description of a single taxon it provides detailed information about a particular species it's in with the overall taxonomy and classification in today's scenario when many plant and animal species are endangered ADEs play a crucial role in studying the important facets of living organisms and saving important information about them for future reference