Kingdoms of Life - Animals, Plants, Fungi, Protoctists, Bacteria and Viruses #1

in today's video we're going to take a look at the key features and differences between animals plants fungi protocols bacteria and viruses and the aim of this video is to give you an overview of what they all are so don't worry about remembering everything i just want you to understand what makes them all different if we exclude viruses for a second these other five groups are the five kingdoms of life so almost all living organisms will be in one of these five groups viruses though are the odd one out because as we'll see later they're

not actually living organisms so aren't in any of the kingdoms of life the other thing that i want to point out before we go through each of them individually is that these four animals plants fungi and protractivists are all eukaryotes or eukaryotic organisms this means they're made up of eukaryotic cells which have certain things in common like the fact that their dna is in the form of chromosomes or that their dna is found in a nucleus on the other hand bacteria are classed as prokaryotes so we sometimes call them prokaryotic organisms and they don't have

a nucleus their dna is just loose in a cell they're also between 10 and 100 times smaller than eukaryotic cells and remember viruses don't count as organisms so they don't get classed as eukaryotic or prokaryotic but for perspective they're another 10 to 100 times smaller than prokaryotic cells so let's now run through all of these groups one by one starting with animals you probably know this kingdom pretty well already so there's not too much to say although we don't know for sure our best estimate is that there's somewhere between 5 and 10 million different species

of animals on earth ranging from humans to chickens to ladybirds to lionfish what all animals have in common though is that they're multicellular they're heterotrophs and most of them reproduce sexually the term multicellular just means that each individual organism is made up of loads of cells rather than just one for example it's thought that an adult human is made up of around 40 trillion cells meanwhile heterotrophs just means that animals have to get their energy from other organisms for example we have to eat plants or other animals in order to get the energy that we

need moving on to plants this kingdom is pretty familiar as well and probably includes around three 300 000 species ranging from redwood trees to bee orchids to tomato plants to water lilies like animals plants are multicellular so they're made up of lots of different cells but importantly they are autotrophs rather than heterotrophs this means that they get their energy from the sun using photosynthesis rather than by consuming other organisms next up we have fungi which are a bit harder to explain some fungi like the mushrooms that you might eat or the molds that can spoil

your food are multi-solar organisms but other fungi like the yeast that we use for baking bread are unicellular which means single celled so each cell is its own organism although some fungi look a bit like plants a key difference is that fungi can't photosynthesize instead they have to get their energy from other organisms like animals do so they count as heterotrophs weirdly though we often refer to fungi as saprotrophs instead because most fungi feed using saprotrophic nutrition this is a process whereby they secrete digestive enzymes onto some food outside of their body wait for the

enzymes to break down the food and then absorb the broken down nutrients back into their body so they're basically doing digestion outside of their body another key feature of fungi is that some of the multi-solar ones have a body called a mycelium which is made up of loads of little thread-like structures called hyphae so just remember that loads of hyphae together make up a mycelium another thing to note is that although it's pretty rare some fungi can be considered pathogens which means they can cause disease in humans for example it's a fungus that causes athlete's

foot if you move on to protractists the first thing that i want to clarify here is that the terms protractists protractista protists and protester all mean basically the same thing so don't worry about which word you use they all refer to the same in kingdom of organisms but for this video i'll use the term protocolists nearly all predoctors are unicellular so single-celled organisms but there's still a huge amount of variety between the different species for example some species like chlorella or euglena are a bit like plant cells in that they have chloroplasts which allow them

to photosynthesize whereas other species like amoeba are more like animal cells and have to consume other organisms to get their energy last point to mention is that most protocols have nothing to do with humans but a few of them do count as pathogens and can cause disease for example the species plasmodium is a thing that causes malaria next we have bacteria which we'll be coming back to in other videos because there's loads of interesting stuff to know about them but for the basics these are single-celled organisms that live just about everywhere you can imagine including

on your skin and in your intestines although some species of bacteria can photosynthesize and none of them have chloroplasts and most of them feed off other organisms either living organisms like ourselves or dead ones like fallen leaves scientists think that there are probably way more species of bacteria than all of the other kingdoms combined and although a few of them can cause disease like salmonella which can cause food poisoning most of them don't have anything to do with humans and many others are actually really helpful like the bacteria in our intestines which help us to

digest our food lastly we have viruses which are basically super tiny particles it's actually really hard to imagine just how small the viruses are but to give you a reference you'd be able to fit almost a million of them across the width of a single fingernail now we call them particles because they don't count as cells and remember they're not living at all viruses come in loads of different shapes and sizes so it's hard to be too specific but their basic structure involves a protein coat around the outside surrounding some genetic material on the inside

which could be dna or rna the main thing to remember about viruses is that they can only reproduce inside living cells so they have to infect other organisms like animals plants protocols fungi or bacteria and use their cells to replicate because of this we call them parasites which just means that they depend on another organism to grow and reproduce for example they can't reproduce without infecting something like an animal or bacteria one last thing to add is that unlike the other groups that we've seen so far all viruses can be thought of as pathogens because

they always cause harm to the other living organisms when they use their cells to reproduce a few examples of viruses include the influenza virus which causes influenza tobacco mosaic virus which affects tobacco and tomato plants hiv which can cause aids and of course covet 19. anyway that's everything for today's video so i hope that was helpful for you as i said at the beginning the main thing i wanted you to take away from this is just a general understanding of the differences between these different groups of organisms there was a lot of detail here and

the important thing wasn't remembering at all but just getting that sense of what they are so if you did find it helpful please do give us a like and subscribe because it really helps us grow and we'll see you again soon you