The diversity of life has been divided into six kingdoms, with the most recognizable being Animalia. The Eukarya domain is composed of both single-celled and multicellular organisms, including animal, plant, fungus, and protist. This domain includes several kingdoms, such as phytoplankton and euglena.
Protists are organisms belonging to the kingdom Protista, which are eukaryotic, meaning they have complex cell structures and are mostly unicellular. They are divided into three sub-categories: animal-like, plant-like, and fungus-like.
Animarial is the most evolved kingdom, divided into two large groups – vertebrates and invertebrates. These animals are multi-celled, heterotrophic, and can live in water, soil, and even living bodies. Protists vary greatly in organization, with some being single-celled, others syncytial, and still others being eukaryotes.
Archaea are prokaryotes, single-celled organisms without a nucleus. Bacteria (or eubacteria) are also unicellular prokaryotes. The kingdom best described here is Kingdom Animalia, which consists of both single-celled and multicellular organisms.
The diversity of life cycles and life histories can easily emerge at the origin of multicellularity, shaped by ancestral constraints and ecological conditions. The most influential system in this study is the kingdom Protista, which comprises eukaryotic, single-celled organisms with a wide variety of lifestyles.
📹 Euglenoids: Single-Celled Shapeshifters
Euglenoids have had a very, very long time to evolve, and that has led to the things they have evolved into being extremely …
What is the diverse kingdom of mostly unicellular organisms?
The Protista are a diverse group of unicellular eukaryotic organisms found in various habitats, including terrestrial, aquatic, and marine environments. They can be free-living forms or parasites of other protists, fungi, plants, and animals. ScienceDirect uses cookies and all rights are reserved for text and data mining, AI training, and similar technologies. Open access content is licensed under Creative Commons terms.
In which kingdom are you most likely to find unicellular organisms?
The kingdom Protista is a group of unicellular eukaryotic organisms that are microscopic in size. It encompasses a diverse range of species, including flagellates, diatoms, dinoflagellates, slime molds, sarcodines, ciliates, and protozoans. These organisms possess cell organelles, which are essential for their functioning.
What kingdom is mostly unicellular and has the most diversity?
The Monera kingdom is a group of microscopic living organisms, including prokaryotes such as archaea and bacteria, which are ubiquitous in all habitats and are defined by their single-celled structure and the absence of a defined nucleus.
Which kingdom has the most unicellular organisms?
The kingdom of Protista is a taxonomic category that encompasses all unicellular eukaryotic organisms.
What kingdom is diverse?
The kingdom Protista is regarded as the most diverse due to its extensive range of individuality, which gives rise to a multitude of unique and distinct individuals.
Which kingdom has the maximum diversity?
R. H. Whittaker proposed a five-kingdom system of classification for the living world: Monera, Protista, Fungi, Animalia, and Plantae. Monerans are the simplest unicellular and prokaryotic organisms, lacking a well-defined nucleus and cell organelles. They can be photoautotrophs, chemo-autotrophs, heterotrophic, saprozoic, or symbiotic, such as bacteria, mycoplasma, and blue-green algae. Monera is more diverse than Animalia, Plantae, and Protista.
Animalia includes multicellular and non-green eukaryotes, while Plantae includes multicellular and green eukaryotes but is less diverse than Monera. Protista is simple unicellular eukaryotic organisms, such as paramecium, amoeba, and diatoms. The diversity of microorganisms is influenced by factors such as land, water bodies, climate, pollution, and human interference. It is estimated that there are about 10 million species on Earth, with the presently known number of living species being 1. 7-1. 8 million.
Which kingdom is made of single-celled organisms that typically live in extreme environments?
Archaeans are organisms that can survive in extreme environments, such as thermal vents or hypersaline water, and are extremely abundant in hostile environments. They were not recognized as a major domain of life until recently, when biologists recognized the need to classify living things into plant or animal kingdoms. By the 1970s, a system of Five Kingdoms was accepted, distinguishing between prokaryotic bacteria and the four eukaryotic kingdoms (plants, animals, fungi, and protists).
In the late 1970s, Dr. Carl Woese and his colleagues at the University of Illinois discovered two distinct groups of bacteria that lived at high temperatures or produced methane. They proposed that life be divided into three domains: Eukaryota, Eubacteria, and Archaebacteria. Woese later shortened the term Archaea to Archaea, demonstrating that each group is very different from the others.
Archaeans don’t look much different from bacteria under the microscope, and their unique place among living organisms has gone unrecognized due to their extreme conditions. However, they are as different from bacteria as you are, and the term “Archaebacteria” has been abandoned because they are not bacteria, but Archaea.
Which kingdom has the most diversity?
Kingdom Protista is the most diverse kingdom, encompassing unicellular and multicellular eukaryotic organisms, including algae and protozoa. These organisms are not classified as fungi, plants, or animals; rather, they are included in the kingdom Protista.
Which kingdom has only single-celled organisms?
Monera and Protista are kingdoms with unicellular organisms, with Monera having no nucleus and Protista having nuclei. The UPSC NDA 2 Result with Name was declared based on the written exam held on September 1, 2024. Successful candidates qualified for the interview starting July 2, 2025. The UPSC NDA II 2024 Notification was released for 404 vacancies, with the selection process including a Written Exam and SSB Interview.
What king
dom has the most single-celled organisms?
The kingdom Protista is a large group of single-celled organisms, including bacteria and blue-green algae. It includes about 50, 000 species of protozoans and between 8, 000 and 12, 000 species of algae. Protists are microscopic, have no organs or tissues, and can be free-living on land or in water. They can live in association with other plants and animals and can move by waving tiny hair-like threads. They obtain nutrients through direct absorption, eating other plants and animals, or through photosynthesis.
Bacteria are sizable chunks of food, and predators are microscopic. Protists can be found in deep oceans, shallow puddles, and even in water film between soil particles. All aquatic ecosystems rely on protozoans and algae as the basic links in food chains and nutrient cycles.
What mostly single-celled forms with a wide diversity of lifestyles?
The diverse lifestyles and cell walls containing peptidoglycan observed in eukaryotic and prokaryotic organisms, including green algae, amoeba, paramecium, diatoms, and chytrids, are representative of the two domains of life.
📹 Old & Odd: Archaea, Bacteria & Protists – CrashCourse Biology #35
Hank veers away from human anatomy to teach us about the (mostly) single-celled organisms that make up two of the three …
Glossary: Metaboly – euglanoid movement. Pellicle – membrane which unites the diverse euglanoids. Lorica – Sugary matrix protective covering. Paramylon – carbohydrate stored in the cytoplasm of euglena. Pallmeloid stage – stage which euglena enters, during which it gets enclosed in a clear membrane, which bursts to liberate the divided euglena under favorable conditions. Thanks and please add if I missed any:)
I watched a single Euglena sanguinea swim around and followed until it stopped and began to swim in a circle. As I watched it gradually got a more rounded shape, until it was a perfect circle. At this point I could see the interior was spinning. I watched as 4 compartments began to form. The spinning had stopped and as I watched the 4 compartments began to swim off one at a time. This all took about 40 minutes. It was the longest time I had ever spent viewing a creature. It pays to be patient and not get bored perusal one creature. This was 4 from one! Imagine the birth rate of this creature. No wonder it has been so successful at survival, and it did it all without destroying the planet! Thank you for helping me identify what I saw. This website is amazing! ❤️❤️❤️❤️❤️ Your website makes looking through a real microscope seem totally unnecessary, when nothing I’ve seen compares to the high definition of your scope and camera recording, and on Big Screen HDTV!
It’s impossible to overstate how freaking awesome this website is, from the calm, soothing narration to the crystal-clear imagery to the light, bubbly background music. This episode especially for some reason reminds me of the episode “Plants Are Living Things, Too, Baby” from Space Dandy. It’d be really cool if maybe you guys could do a side-video talking about what organisms most of the life in that episode is based on – and it’s a great show besides!
I’m sooo glad I found this website. At first I was like “what is this ? Some boring cell stuff?”. But oh boy, was I wrong. These articles are real little documentaries. It shows that they are made with a lot of care and love for the topic. The voice that explains what the little guys are up to is funny and still has enough authority to keep us from loosing interest. Most of all, I actually learned something interesting from perusal the clips. Really, Journey to the Microcosmos is a fresh wind blowing through he barren and shallow landscape of Youtube. I actually subscribed when I was in the middle of the first article. You have an admirer for life.
When I started being taught science in school, I really lost my love for science, I associated it with negative emotions and only now is this website really renewing that old love I lost, it’s so lovely and peaceful, and fascinating. It’s scary knowing I’ve missed so much time, but it fills me with life to be reminded of the how wonderful our world is. I know this is might come across as a bit dramatic or exaggerated or cheesy, I’m not sure, but I didn’t realise how much it sucked losing such a great thing, so yeah, thanks Hank, Andrew, James and all of the others we don’t get to see. Also: I want y’all to know that after obsessively perusal Journey into the microcosmos and the vlogbrothers, Ive been introduced to a bunch more nerdy websites that I also adore, and holy macaroni actually learning is so fun!
I really appreciate how carefully you specify magnification and replay speed. Would it be possible to do something similar when you are racking the focus? Give us an idea of how far and how fast the focal plane is moving. It would be really interesting to get a better sense of the depth of these tiny creatures.
I’ve been thinking of getting into a bit of microbiology/ microscopy and this website just happened to spring up and now it’s really an inspiration, I’m planning on dropping a couple grand on a nice scope and some books, along with a sealed grow room used for growing plants, some petre dishes and a mini fridge, a UVG light so things don’t get ‘out of control’ . Thank you Hank, you’ve taught me so much, Thank you so much for your contributions to human knowledge.
I love seeing these articles pop up every week. It’s a nice little break from the day to day grind of life. Life is so busy and stressful, but looking at these tiny creatures just takes me back to being young and forever curious about the natural world. It’s good to be reminded of that feeling! 💎 @8:33 That’s what I’m talking about! 😎
This is such a great article! Our lab has done some research on Euglena gracilis and it has such a cool genome! Not only is it a hodgepodge of at least four (!) different symbiotic organisms that it’s believed were basically swallowed at different points in its evolutionary history, it also has a unique “letter” in its DNA called base J. Base J is usually only found in parasites from the Kinetoplastea class and looks like a T with a glucose molecule stuck to it. Very cool to see these little guys in action!
I remember these guys from when I was a kid. We had to make and edible microorganism model for 6th grade science class and I got this one out of the hat. Made the body out of mint leaves, a single red hot for the eye spot, a single strand of twizzler for the flagellum, and glued the whole thing to the board with cake frosting so it could be eaten when done, unlike most of the models. I spent all this time assuming that they were more or less rigid and moved with the flagella.
I really wish they’d put a light above the specimens so that we can see what these organisms ‘really’ look like, ie their external 3d structure and not just the ‘Flatland X-ray’ version, and to use RGB-UV LEDs to smoothly transition between an transmission and reflection image, and so that different parts can be highlighted by dimming some LEDs some and raising others; what with the availability of cheap LEDs and the obvious advantages of this simple idea it’s annoying but not surprising that this isn’t commonplace, yet the many things one sees that could easily be improved in obvious ways highlight (to me) another negative aspect of Capitalism but I digress. 🙂
The website name feels very appropriate to me – documentary as a form of artistic expression really. One small thing – maybe the music should change? Not that it’s bad or inappropriate (quite the opposite), just there is probably more to explore there as well? We’ve heard these tunes a lot, and as awesome as they are, it would be even better to try and find music that’s a bit more unique, if not to each article, maybe to each family of micro-organisms we’re seeing or something like that? Just a suggestion – it’s great as it is really, but I suppose everyone likes good feedback? 🙂
It’s pretty crazy that cells and us aren’t super different, like could cells be conscious? and playing like, first person perspective qualia of being something wriggling around and eating things and when it had children would that just like split into all its daughters at once so they’ve got a thread of consciousness going since the start of life? that’s cool o.o
As may be established empirically, matter is not essential so that existence may be made subject to it, and be dependent on it. Rather, matter subsists through a meaning, and that meaning is life, it is spirit. Also, as may be established through observation, matter is not the thing served so that everything may be ascribed to it. It is rather the servant; it renders service to the process of the perfection of a truth. And that truth is life. And the fundament of that truth is spirit. Also, as is self-evident, matter is not dominant so that recourse may be made to it or perfections sought from it. Rather, it is dominated; it looks to the decree of some fundament, it is in motion in the way that that decree dictates. And that fundament is life, it is spirit, it is consciousness. Also, as is necessary, matter is not the kernel, it is not the fundament, it is not a settled abode so that events and perfections may be affixed to it or constructed on it. Rather, it is a shell prepared to be split, rent, dissolved; it is a husk, it is froth, it is a form. Consider the following: a creature so minute it can only be seen with a microscope has such acute senses it can hear its friend’s voice, and see its sustenance; it has extremely sensitive and sharp senses. This demonstrates that the effects of life increase and the light of the spirit intensifies in proportion to the reducing and refining of matter. It is as though the more matter is refined and the more we become distanced from our material existences, the closer we draw to the world of the spirit, the world of life, and the world of consciousness; and the more intensely the heat of the spirit and the light of life are manifested.
I am so excited to see all these articles with a range of titles that specifically have interest to me and my new found concern for what’s going on in the micro verse! I see an interesting title “yes! I need to see what this one will uncover!?” But then another article from your website appears which says to reveal something of even more interest to me! Ahhh so much to learn! I just became a Patreon and I have many questions 😅
i came back to watch this after identifying my first ever organisms in my new microscope, it was a whoooole bunch of euglena granulata. i was following a larger, more squishy ciliate that i couldn’t identify around a bit when i noticed that the entire background i was viewing it on was teeming with euglena once i focused my objective a bit. i almost started crying with how beautiful it was, and just sat there perusal them for a while. the little tube i keep their sample in is labeled e for euglena whenever i want to go back and look at them again! thank you all for inspiring me to do this, its made a really big impact on the way i view the world
It’s so easy to forget that all the actions and reactions of these things are happening on a molecular level. Ok, all living things are based on chemistry, but I mean there’s no intermediary like nerves or muscles. Flagella move, not because the cell wants it to, but because it just does due to chemistry. And then shading some part of the cell changes the chemistry a little an the flagellum move differently.
Protists are honestly way too diverse to be classified all into one kingdom. What causes confusion is that the notion of classifying all other organisms as protists suggests that they all share the same phylogeny, which is anything but true.(ie. Brown algae and amoeba do not share recent common ancestors.) A great analogy would be the former system classifying eubacteria and archaea into the domain Monera, which does not truly reflect their evolutionary history (archaea are more closely related to eukaryotes). I hope that many more scientists start to debunk the notion of classifying organisms as “protists” simply because they “don’t fit” and develop a system that truly reflects their evolutionary history (ie. adding more kingdoms–sorry biology students).
I LOVE this Guy/show!!! So glad I took Biology so I can share these with my son. Favorite quotes, “like Daniel Tosh’s mouth, Crap show & piles of barf”!! Call me a geek, but there’s a good chance I’ll watch these for fun even once I’ve finished my final today! Thanks for making science fun, interesting & funny!
These articles are truly excellent! I am hoping, since you indicated on SciShow that you would entertain requests, that you would consider doing an entire series on Microbiology. Your Bio series has been an enormous help as has the Chemistry series. An entire series that really gets into life at the microscopic level would be really helpful for us pre-health care sorts. What do you think??
Sorry to be picky, but just a slight correction. The bacterial genetic material is not made up of just plasmids. Bacteria have a single, larger circular chromosome that is VERY different from eukaryotic chromosomes in terms of its organization and regulation, but is nevertheless a chromosome. Plasmids are additions to the chromosome, that the bacterium can pick up from other bacterial cells. Plasmids are also circular (slightly confusing) but much smaller than the main chromosome. They are completely separate from the chromosome, and even replicate autonomously. They generally carry genes encoding functions that are not absolutely necessary to the survival of the bacterium, but are a nice little additional thing (like antibiotic resistance, for instance).
It must be noted that he says Archaea are the oldest life forms on earth. This is FALSE. Bacteria are the oldest life form on Earth. They have fossil remains the predate archaea (3.6 billion years ago). Furthermore, the phylogenetic tree indicates that bacteria came first, then archaea, then eukaryotic organisms.
Nice explaination, though I think you misspoke a bit. As you said chloroplasts resulted from endosymbiosis of cyanobacteria. So the answer to his question would be no, cyanobacteria do not have chloroplasts (they became chloroplasts after a eukaryote cell had endocytosed them). Also (sorry to be nitt picky) chloroplasts are still termed organelles even though they result from endosymbiosis.
Um, just a suggestion that would help ppl like me who are visual. At around 2:20, Hank recaps a bit of info and lists differences between Archea, Bacteria and Protists, euka-I-can’t-remember and the other thing (?) – anyway, it’d be helpful when he does this to put a column on each side of him and print the word that goes with the one thing or the other and leave it there for the duration of comparison. It’d help a lot. I litteraly couldn’t retain any info during that part. 🙁 Thanks 🙂
Did they change the groups of protists? In my textbook, the group them in 6 supergroups: Excavata (ie. diplomonads, euglenozoans), Chromaveolata (aveolates, stamenopiles), Rhizaria (forams, radiolarians), Archaeplastida (red algae, green algae), Amoebazoa (slime molds, plasmodials), and opisthokonta (choanoflagellates, mesomycetozoa) ….
You are correct, I said “strand” when I meant “fragment” or “chromosome”. As in, eukaryotes usually have their genome in various linear fragments (that is, chromosomes) while prokaryotes usually have theirs in one single circular fragment. But both contain, of course, two strands of DNA. That’ll teach me to try and correct people too early in the morning. I will note that some bacteria have multiple chromosomes and even linear ones, because they are weird, but yeah usually only one circular one
Some viruses will naturally integrate into the genome depending on conditions (I only know of some phage doing this – which is the name for viruses that infect bacteria) but they also have mechanisms to get themselves out again. I think these ancient integration events happened at a really low frequency and I think it’s thought that they were weird accidents. (But I haven’t studied this in about a year so I’m no expert if you’re interested I’d try the literature)
There’s a difference between rapidly spewing information and teaching. IMHO, it would be good to add some appropriate pauses, or careful repetition, to allow the important info in these vids to sink in. This could greatly improve recall–valuable evidence of learning. Of course, it depends on the intent: to impress or to inform. I believe these vids could do a better job of informing, if that’s their intent. Many thx.
I realize I’ve come a bit late to the party, but I wish you would do a whole episode on just the slime molds, or the xenophyta, like the sailor’s eyeball that you mentioned. They’re so odd and alien in their reproduction, and I’m fascinated by the idea of a macroscopic, single cell having locomotion.
I can’t help but feel like there was some misinformation in the article. Recent studies show Archaea are more closely related to Eukarya. Meaning Archaea arriving first, then bacteria evolved from them, then Eukarya evolved from bacteria, is not the correct evolutionary cycle. Modern Archaea and Eukarya are now thought to have descended from the same ancestor, and bacteria were the first lifeforms. At least that’s the current ideaology in the biology classes
Just a thought, but couldn’t we conceivably use CRISPR editing to create bacteria with genes that make it no longer immune to antibiotics or unable to develop immunity to them, or both in such a way that the genes would always be dominant? We could then release these modified bacteria into the environment and in a few hundred generations they could completely proliferate. Just thinking out loud here.
A couple of thangs: 1) Gram-positive and gram-negative bacteria have different thicknesses of cell *walls*, not cell membranes. Cell membranes only come in one thickness. 2) It’s extremely important to note that no actual taxonomists count Protista as a kingdom anymore. It’s been broken up into a whole bunch of kingdoms like Rhizaria, Excavata and Chromista (the exact number depends on whom you ask). It’s a mess, true, but it’s a much more realistic mess than the five-kingdom system.
So I don’t know how we would find the oldest integration, when they’re figuring out when this virus-like thing possibly entered the genome they look at what organisms share it, for example is this DNA bit in all humans or just a subset (I’m using humans as an example just because I know the most about this in reference to humans).
I love your content and love your charisma in presenting it. If I could make a suggestion – old people like me would regard you as much more professional if you would grow out that facial hair into some recognizable form (goatee, beard, chops, whatever) or opt for a clean shaven look. I don’t find it detracting, but I can’t help but think you just got out of bed – as opposed to showed up for work and had a meeting about today’s content.
great article. BUT! plasmids are self replicating genetic material that does not form part of the main circular DNA of bacteria. think of them of tiny little versions of the main circular DNA of the Microoganism, they code for certain adaptive traits like antibiotic resistance but they aren’t strictly necessary for the organism to complete its life cycle, meaning that they can be removed. we use them to transfer genes from one organism to another.
Yay, microbiology! I do research on bacteria, so I’m glad you’re teaching folks about them. One point: Gram negative and Gram positive refers to differences in their cell wall, not cell membrane. (All living cells have membranes, made out of phospholipid; bacteria also have cell walls made out of peptidoglycan.)
As a college graduate from a distinguished University, and now teacher’s assisstant at said University, I can honestly say that this is EXACTLY what they teach at the college level. This is called CRASH COURSE for a reason; of course the college level will go more in depth talking about apicomplexa’s pseudopods, or ciliophora’s radula, but this is the basis of the chapters in our bio books. FUNDAMENTALS is what will take a student far, not just expecting to be spoon fed. Thank you so much Hank!!
It’s linguistically neutral. Most people on Earth don’t speak English (though I think a plurality do). Rather than picking a preferred language that people still speak, it’s probably best to pick ancient languages that a) were historically used for this kind of thing and that b) because nobody speaks does not indicate a linguistic preference.
I HATE him Lol.. No, really, after studying medicine for a while and having to deal with all the big Greek & Latin words that we have to learn, words I can’t even write, how about pronounce? (though I’m not an English native speaker) I kinda prefer English over Latin & Greek words. It’s nothing against a system that’s been there for hundreds of years, just that it would been much easier… but I agree, there’s no use in flipping a whole system just because almost everyone speaks English now =\\
No, protozoans are unicellular by definition, although some simple colonial forms (e.g. choanoflagellates, the precursor to sponges) are still considered protozoans. 🙂 Also note that “protozoa” and “algae” are artificial groupings, not natural ones. Sponges are a distinct lineage and as such a natural grouping.
I’ve done a bit of reading now, there’s an excellent Eukaryota table at the end of the “Opisthokonta” article that lays out the multitude of groups; The plants, animals & fungi are only the most prominent members. There’s even a group called the Ciliates which are like simple animals in a single cell.
I would love to see a crash course episode on mushrooms. I read they cellularly have more in common with animals than with plants; some species actually move (like seriously move…here today – there tomorrow, kinda move) ; some can grow full-size over night; some are poisonous and some cures our illnesses. I wanna know more about these weird living things!
Latin used to be spoken the world over, and was known as the language of science. While it’s a tradition to name species in Lation (or Greek) it’s not a hard and fast rule. EG the dinosaurs “Drinker nisti”, named for Edward Drinker Cope and a tech school, or “Mei long”, which is Chinese for ‘sleeping dragon’. Not all species have a common name, eg rare or exotic species, fossil remains, or new discoveries, eg Elysia viridis.
Question: When looking at “more primitive” living things, like algae, how do we know that they haven’t also been evolving for the last x-billion years? It’s the same problem as with monkeys and humans—we evolved from a common ancestor with modern-day monkeys, not from modern-day monkeys. Have scientists ever thought about what algae and other creatures were like millions of years ago? Why do they act like evolution has stopped for these and other things?
You are correct not all species do have a common name. That is more in practice for communities since it’s easier to say white oak tree instead of Quercus alba. Common names are created in particular subjects by certain authorities, in an attempt to make it possible for members of the general public (including interested parties such as fishermen, farmers etc.) to refer to a species of organism without needing to be able to memorize the Latin scientific name. Microbes don’t get common names.
…Because that’s how it’s always been done. In science there are two names that are used. There is the common name and the scientific name. The common name for what you just mentioned is in fact Dog Vomit Slime Mold because of appearance and morphology. The scientific name though which it MUST be given is Fuligo septica. No matter what organism you find it’ll always have a common name and a scientific name.
As a person who has a degree in Biology and specialized in Microbiology I just had to stop the article around 3 minutes and address something. He was wrong about what he said with chromosomes and plasmids. Prokaryotic DNA is in fact found as a single circular (although very complex and wound) chromosome. A plasmid is a free floating extra-chromosomal (not part of the chromosome) piece of DNA that confers special instructions such as antibiotic resistance and the like.
In all honesty, I think with these kinds of subjects you should include more pictures for those who don’t already know the subject. Learning through multiple senses is always better than one. Your beautiful face, is not a learning media 😉 I find that you talk and show the camera on you when you’re explaining new concepts and a picture or two would go a long way. Love the articles though 😀 Keep it up References: 4th year BioMed Student
There is creationist pseudo-science. Big difference. The ‘faith’ one needs to believe in science is completely different from religious faith. As in, “Wow. Scientists have put us on the moon, created iPads, etc. They must know what they’re doing. I have faith in their approach to understanding the nature of the universe because they have demonstrated the validity of science.”
totally ! gram-positive bacteria have multiple layers of peptidoglycan walls that cross over each other (held together by amino acids) gram-negative bacteria have one layer (or very few layers) of peptidoglycan and is reinforced by an outermembrane. But both classifications DO have cytoplasmic membranes underneath the cell wall, of about 6-8nm thick. Less than 1% of all known bacteria is harmful to humans.
The whole egg isn’t the cell. The actual cell or ovum is located on the surface of a bird’s yolk. I believe it’s called the germinal disc and it is this that contains the nucleus. You can actually see it when you crack an egg into a frying pan but it is very faint and pale white. (still relatively very large for a cell) The yolk and albumen are merely food for the germinal disc.
Wow, I get to correct Hank. Prokaryotes DO have chromosomal DNA, although it is usually circular and usually in only one strand, as opposed to eukaryotes’ multiple linear strands. Plasmids are something else altogether, mobile genetic elements separate from the chromosome which replicate independently and can be transmitted between individuals. So a bacterium has its chromosome, and in addition may have a number of plasmids also encoding information inside it.
gram positive bacteria actually have a thick cell wall (peptidoglycan layer) not cell membrane..cell membranes, i.e. lipid bilayers in bacteria and eukaryota or monolayers in archaea, are usually about the same thickness (~4 nm) in all cells..gram negative bacteria on the other hand posess a second membrane called the outer membrane..also i’d like to stress that by far most bacteria are harmless (you kind of make them sound like this superevil domain of life which they are not)..
Viruses have evolved a lot a lot (which is A LOT) there are definitely people who study virus evolution, etc. (see paleovirology for something I consider way way cool). Current viruses are constantly evolving so by looking at viruses fragments that have become part of an organisms genome you’re looking at a “fossilized” virus and I believe that’s at least part of how they study viral ancestry.
No. It’s in the play list or the website page at the very least, but it is many, many episodes back. As far as I could tell the only Crash Course Episode ever removed was the World History episode on Judaism, which wasn’t really removed so much as it was elongated to create the episode on Judaism and Christianity, which would otherwise been two half-length episodes. (or maybe they were one episode to begin with and my sleep deprived brain was seeing double)
Nice vid as always, but some of your facts were a little off. Most sources (books, internet, and teachers) state that Bacteria are older than Archea, and DNA analysis proved that we (Protists) are more closely related to Archea than Bacteria which means we descended from Archea and not from Bacteria. Still you did a better job explaining this stuff than my University teacher 🙂
I’m pretty sure mycobacterium like tb and leprosy are acid-fast bacteria. Which means that they don’t apply to the gram staining classification. But technically that should be considered gram negative because they lack the outer peptidoglycan layer. Also why not talk about endosymbiosis it’s the coolest.
Also there is a way more important reason than because that’s how it’s always been done. (In fact that’s no reason at all) And this reason is because for non-English speaking people it would be pretty exhausting to learn all the English names. So we all use the same nomenclature. And that is normally Greek, Latin or Latin-sounding 😉
Why not name them all in English? Because they’ve been naming organisms in Latin for centuries. It’d be idiotic to change it all now on a whim because a couple people think it’s somehow “pretentious”. The Latin naming system was devised in 1753 by Swedish scientist Carl Linnaeus and it was so effective it has been used since.
They pop and squirt liquid. Their just like water balloons but with a hard shell. I have plenty of experience with them in my Reef tank, and diatoms, and red slime algae. Most grow to the size of a marble and you can twist them off the rock they anchor on and pull them out without popping…Or my Emerald crab pops them and eats the hard shell.
I have to agree the pronunciation seems a bit off, but it is a American English versus English English thing. It’s funny though because when saying Fungus Hank doesn’t say FUN-JUS, but when saying Fungi it’s just so many shades of wrong. Before checking google on how to pronounce it, remember that is the American English version :).
eukaryotes and archaea share a common ancestor. THAT common ancestor shares a common ancestor with bacteria. meaning bacteria probably evolved before eukaryotes. i hope that sortve explains your query. also mitochondria and chloroplasts are classed as bacterial organisms due to them containing 70S ribosomes.
No, they are not conventionally considered “living” because they are very odd. Living organisms are considered to have the following traits: Use Energy, Produce waste, Reproduce, adapt, and are made of RNA or DNA. The virus is weird because it contains RNA and can mutate, but doesn’t energy, doesn’t create waste, and cannot reproduce on its own.
As far as I know we don’t know but because viruses require a host cell to replicate I know there’s thought that they came from some accidents where some DNA or RNA (from a cell, like a plasmid or something) packaged itself and took off to be a virus. (A plasmid is a small circular bit of DNA that bacteria have in addition to their genomic DNA)
i know scishow already did a show on viruses but im wondering were viruses 1st and then evolved into these kind of things ( which i doubt) or if these evolved into viruses once DNA had evolved enough for them to take over ( which i think more likely) or is there an actual reason i didnt think of, or is there even an explination?
Hank, yo, you need to get some shirts that fit. Not that your giant shirt detracts from your insightful observations about single-celled organisms (and a very few multicellular ones), but it IS a little distracting. I keep thinking, wait! It’s long enough for his arms, but it looks like his torso’s in a very demure-colored circus tent! What’s going on?