we start the video two of chapter two which is on the o level biology syllabus five zero nine zero and this is the new syllabus for 2023. now in this uh video we're going to discuss this 2.2 which is features of organisms state the main features used to place organisms into one of the five kingdoms animal plant fungus prokaryote prototist state the main features used to place organism into groups within the animal kingdom limited to the main groups vertebrates mammals birds reptiles amphibian and fish then the main group of arthropods in which we have myriapods insects arachnids and crustaceans state the main features used to place organism into groups within the plant kingdom limited to only two ferns and flowering plants and in the flowering plants we have to do dicotyledons and melanophobal agents then classify organisms you use the features using the features identified in all these three subdivisions state the main features are virus limited to protein coat and genetic material understand that the virus can only replicate in living cells so their total parasites now i'm going to go into more details about 2.2 in this video now the first thing is to place all the organisms according to their features into a five kingdom classification means we can put all the living organisms into five categories the first one is animal which is usually multicellular which is always multicellular not usually plants are always multicellular fungus are multicellular but some unicellular like we have yeast which is a unicellular fungus but mushroom is a multicellular fungus then prokaryotes are only bacteria so they'll always be unicellular protrautista are mostly unicellular but it could be some multi they want you to be talking about a few of the very multicellular ones as well and the example is protozoa plasmodium which is the causative organism of malaria so please remember now that is not a bacteria bacteria something else bacterial diseases are cured by antibiotics protozoa diseases are not cured by antibiotics now another very good uh way of you know i want you to sort of memorize this so i want to go to these different uh diagrams on this so this is the animal you can say multi-cellular here and then you can say plant is always multicellular tree you remember always keep a tree in mind when you're talking a plant and animals keep a fish or any you can keep a human being or a monkey in mind then fungi a multi-cellular cell the more important thing is that in animals there are no cell walls in plants the cell walls are made up of cellulose and in fungi the cell walls are not made up of cellulose but they're made of chitin which is something else which is not different chemically it's different now protractors look mostly unicel a few are multicellular so the prototypes are unicellular mostly uh complex cell structures but they have a proper nucleus now proper nucleus is where proper nucleus is here proper nucleus is here and fungi also have a proper nucleus so all these four have proper nucleus but this one does not have a proper nucleus so i like to do the comparison you know what is present in this and what is not present in that so that is makes you all remember it very well so protractors do have a nucleus but prokaryotes which are bacteria prokaryotes are bacteria so please remember them a very easy way to remember is them like this bp but then p is also prototype so be careful prokaryotes and if you look at very advanced books of course these are all then classified under eukaryotes but eukaryotes is not mentioned in your syllabus so i'm not going to be talking about that so prokaryotes and eukaryotes animal a we call it animalia but animals plants fungus and pro doctors so these are all the ones which have a nucleus only the ones which are bacteria do not have a nucleus now do not have a proper nuclear membrane now looking at a little more detail you know just giving a little more points that i want to give you from my point of view uh animals uh you know monkeys elephants examples proper nucleus which means that their prokaryo then means they're eukaryotes they're all multicellular they have membrane-bound organelles like mitochondria are present and they're heterotrophs they can't make their own food they're not like plants convert light energy to chemical energy but they can eat ready-made food and then of course digest it and absorb it then plants proper nucleus again eukaryote autotrophs and they're all multicellular and chloroplasts they convert light energy into chemical energy and examples are a mango tree or a rose bush then we have fungus mushroom yeast some multicellular some unicellular because you have to remember the yeast cell you have to remember yeast cell is a fungus so they are unicellular but mostly they are multi-cell like a mushroom is a multicellular there are no chloroplasts they cannot make their own food they are not autotrophs they release enzymes and extracellular digestion takes place they have a proper nucleus so they will be classified under eukaryotes this cell wall is made up of chitin it's not cellulose like in plants that cellulose then we come to the next category pro top test they are mostly unicellular some do not have a cell wall some do have a cell wall they have a proper nucleus they are eukaryotes there is some autotrophs some heterotrophs the autotroph is chlorella which i've given you here and amoeba plasmodium these are the protozoas which are the unicellular animals unicellular animals so that's make it easy for you to remember plasmodium causes malaria which you will study later and so coming to the next one prokaryotes they're always bacteria so bp remember bacteria prokaryotes unicellular there's no nucleus there's no nuclear membrane when i say no nucleus i mean no nuclear membrane the cell wall is not made of cellulose not of chitin but it's made up of peptidoglycan peptido means there's a protein present and glycan means there's a carbohydrate present glycogen so make sense if you understand them from correlating other words with it it has a loop of dna and the ribosome is present so if there is dna and ribosomes that means they can make their own proteins extracellular digestion takes place example is e coli which is a form of bacteria now the next topic is we have to know the features of the animal kingdom by the main group of vertebrates now what are vertebrates vertebrates are those which have a vertebral column which have a backbone and they are non-vertebrates which don't have a backbone now the main headings which you have to understand is birds fish amphibians reptiles and mammals and i've made a demonic for a bee farm so birds fish amphibians reptiles and mammals first let's get these name because we need to remember these and it's difficult for you all to remember things because you are the generation which finds it difficult to memorize stuff so it's okay well you have to make some mnemonics to actually remember these uh terms so birds fish amphibians reptiles and mammals now what are vertebrates the animal with a skeleton and i have shown you this vertebral column it is made of the cervical vertebrae and the thoracic and the lumbar and the sacrum but you don't have to know these names but i just want you to understand what are vertebrates and the animals without the skeleton are these ones which are the ones which i do not have a skeleton these are the animals which have a skeleton then if you look at this you know what is the vertebral column it's made up of vertebrae and these vertebraes are put together and you've got the spinal cord here so the spinal cord passes through this uh there's a hole which is continuous and the spinal cord passes through that and you have this is the body of the vertebrae and the body the vertebrae is made up of bones and in between the vertebrae you've got a disc which sometimes you know people say they have a slip disc so i just want to know a little more about the vertebral column and what it actually is made up of now whenever you're doing a comparison it is always a good idea to compare like with light like for instance now we've got all these here now let's look at it amphibian are cold-blooded so i'm writing c here cold-blooded now these are warm blooded this is again cold-blooded then warm blooded and then cold blooded so you see only mammals and birds are warm blooded reptiles fish and amphibians are cold blooded then coming to lungs and gills now amphibians you can see the frog and that's a very good example they can hold the lungs and they also have gills so they can live in the water as well they can live on land now these breathe with lungs birds have lungs now similarly these fish have gills they don't have lungs at all because they stay in the water they can't come on land and mammals have as you all know we all are have lungs so lungs and also the reptiles have lungs they do not have gills so lungs and gills is only an amphibian then this is only lungs birds only have lungs then fish have gills they don't have any lungs man will have lungs and reptiles have lungs so you do a comparative analysis ambibian lungs and gills birds lungs fish only gills mammal lungs and reptile lungs so this is how you do a comparison between these different now let's come to another thing now about the skin the skin is the most important so the amphibians have a smooth moist skin now the warm blooded have birds do not have skin they have feathers then here we have the fish they have they lay eggs they have fins the mammals have hair or fur on their skin and these reptiles of course have a very dry scaly skin so you must keep one in mind and then think of them like reptiles you can think of one and then mammal and fish and bird and keep an example in your mind and make a mental map of it and then of course you can understand it now another slightly more detailed one amphibians thin and humid skin transformation through their life cycle they change their breathing methods lungs gills and skin they're born from eggs cold blooded animals they live on the ground and water fish they live under water they breathe through gills some of them have scales covering their bodies pins help them to move under water cold blooded animals they're born from eggs reptiles the longest lived species in the planet cold blooded body covered with scales or shell they cannot chew they are born from egg they live on the ground or in the water birds covered with feathers they usually have porous lightweight bones to allow them to fly they live they live flying or on the ground their wings to fly their mouths are toothless beaks warm blooded animals they're born from eggs mammals they're born alive from mothers they breathe through lungs they live in the water the air on the ground then their body is covered by fur warm blooded the next topic is main group of arthropods so they have made a mnemonic for that for you all to remember crustaceans arachnids media pods and insects the first thing is all arthropods have three key features number one they have a tough exoskeleton you see we all have an endoskeleton it's inside we have the muscles on top of it they have an exoskeleton they have jointed appendages that's why they're called arthropods pods and they have a segmented body so these are the three things which are common to all arthropods arthropods examples are crabs lobsters centipedes spiders grasshoppers and scorpions they are invertebrates and they have an external skeleton and they have a segmented body you have jointed attachments called appendages the wings mouth parts and legs arthro means joint and borders means foot or leg they have bilateral symmetry they have an open circulatory system and they have a digestive system with two openings and they reproduce sexually this is the jointed fourth largest phylum nine hundred thousand species compound is typical insect spiders crustaceans millipedes scorpion sticks now i would like to talk about some parts of the arthropod first of all the body is divided into three segments head thorax and abdomen right so three parts head thorax and abdomen but some have the head and the thorax are joined and that's called the phallothorax and then there's the abdomen so the two differences because you're going to be able to then differentiate between the different ones which ones have a phallothorax and abdomen which one have a head thorax and abdomen so the head has mouth parts for feeding and various types of eyes simple eyes compound eyes the thorax is the middle body region to which legs and wings are attached the abdom abdomen is the posterior end and bears additional legs and contains digestive structures and the reproductive organs and let's be very clear about certain wordings that we are going to be using here segmented body segmented body means that the body is not in one continuous but it's made of small tiny tiny segments joined together then there's an external skeleton which you've seen in lobsters and crabs even in a cockroach you've got the external skeleton because when you step on it you know it makes that noise breaking something and that is the shell actually which cracks and jointed appendages so these are the words you must know before we go on to details of this group characteristics of insects there are segments of fuse they have a head compound eyes mouth parts sucking chewing glamping other paired appendages thorax three pairs of legs wings none one or two pair so wings is very variable there can be no wings they can be one they can be two pairs and abdomen has the visceral reproduction and digestion now just a quick look at the different lens uh simple lens eye simple corneal eye there's no lens in it and then there's a compound eye and insects and crustaceans uh some molluscs and analytes of course also have compound eyes so you must be able to make out which is a simple ion which is a compound eye now a quick look at the different uh weeds they have crustaceans they have a crust i mean they have a hard shell and you can see this is the crab and the lobsters all more than four pairs of jointed legs that's the most important thing and they have an outer very thick uh hard crust then media pods are the ones which have media media means many pods means many feet there are many similar segments each with at least one pair of jointed legs so there's every segment and every segment has a leg joint pair of legs jointed so the legs have joints in them so many many segments and then each one has a pair of legs and we'll see some examples of this which you can see here on this side then insect time sector insecticides insect body divided into head forex and abdomen six jointed legs and four wings attached to the thorax but maybe less of force as well then arachnids now these are the ones which have a head and a phallothorax c and an h caphylothorax and head and you have a c and an h here so fellow thorax and had four pairs of jointed legs now this is the best comparison that i could possibly get and i've done this for you all to understand so key features of insect crustaceans various pods and arachnids of course the arthropods we have discussed earlier is that they have an invertebrate they have no backbone they have a waterproof exoskeleton they have a segmented body and they have jointed legs now let's do a comparison three pairs of jointed legs more than four pairs of legs four pairs of legs each segment has jointed legs more than nine pairs then next let's do another one one or two pairs of wings here we don't have any wings no wings and here we have no wings so wings are only present in insects this is a very key feature that you will understand to remember that the other crustaceans mariapods and arachnids do not have any wings then look at another point now if you look at all these you know simultaneously then you can understand them a little better three body parts head torx abdomen i'm using the same color three body parts head thorax and abdomen in the crustaceans there's the phallothorax and the abdomen in the arachnids again there is the cappella thorax and the abdomen and i have talked about the cophylophonics earlier here of course there is no heterothorax and abdomen is just a segmented body throughout there is no demarcation of head thorax and abdomen then let's come to another very interesting point is the compound eyes there's one pair of compound eyes here we have also compound eyes you do not have any mention of any there is several sorry there are several pairs of simple eyes here yes and here they have simple eyes as well so arachnids and media pods have symbolized while insects have compound eyes and crustaceans have compound eyes so compound eyes in insects compound eyes and crustaceans simple eyes in arachnids and simple eyes in maria parts so this is how we will do a comparison then another one very nice one is uh antony so one pair of antennae here here we have two pairs of antennae in crustaceans in arachnids again two pairs of antennae and in one pair of antennae essence organs and dark habitats so one pair of antennae in insects crustaceans have two pairs of antennae and arachnids have two pairs of antennae and media pods have one pair of antennae so insects and maria potts have one pair of antennae and crustaceans and arachnids of two pairs of phantoms i know it's very difficult but i'm trying to make it easier for you to remember these i hope it's becoming easier now coming to the classification of plants we only have to study two uh different categories and the one is number one plants which make seeds and plants which do not make seeds so in the seeds one what we have to understand is the flowering plants and in the ones which do not make seeds we have to study the ferns so the ferns is the one that we have to study and the flowering plants is the one that we have to study now in the flowering plants you can see we have to study the monocots and the diocodes so monocotyledons and dicotyledons are the ones in which the seeds have one cotyledon or two cartilage mono means one die means two and in the non-flowering we have got to study the funds now the key features of flowering plants is they have root stems and leaves and they have xylem and phloem and they reproduce by producing seeds so they'd have a flower and then we'd have we'd study flowering and seed seed production and fertilization and seed production then seed dispersal and seeds are produced inside the ovary inside the flower and asexual reproduction is also possible in certain plants now the ferns they're different now i've given you pictures of this this is a flowering plant and this is a fun ferns and their relatives are vascular tissue and use spores to reproduce and vascular plants are better suited to live on life on land than on our non-vascular plants so vascular plants means they have xylem and phloem but they do not produce any seed so they have no flowers and they have no flowers no no fuel no seeds and they produced by a special mechanism which is called the used force to reproduce now flowering plants are classified into two different categories monocots and dicot and the leaf shape is very important plus the seed is very important now as you can see here i put a diagram of the seeds dicotylation seeds have two cotyledons and this is the cotyledons so they have two cotyledons you see this in peanuts then the maize seed you see there's only one quarterly done so examples are in the bean seed is a dicot maize corn which you eat is monocot but the important other differences between the leaves and the venetian leaf veins now you can see these are parallel veins and they are found in more in grasses and if you just look at the grass go out and look at the grass you can see these leaves and this was a network of veins you see this is the mid rib and then there's a network of veins now there's no such network in the monocots but this is a network which you see in the dicot so branching network of veins while these veins are called parallel venation or parallel veins and the seed leaf means we were talking about the dicot is one and there's two so these are the main differences between monocot and dicot thank you for watching the another video will follow which will have the last part of it the virus part in it and it will have some questions on this chapter so that i can help you understand what is the what is the amount of level of understanding that you must have to be able to do the mcqs on this thank you very much thank you for subscribing and thank you for watching