Hey there. Welcome to clutch prep microbiology. My name is Jason and I'll be your instructor throughout this course. If you have any questions about the content in our videos, feel free to post your questions in the comments section of the video. And one of our tutors will get back to you as soon as possible. Now that being said let's go on and get started with our introduction to microbiology. And so microbiology can be defined as the scientific study of microbes which are organisms and infectious agents that are simply too small to be seen by the naked eye alone. And so in the field of microbiology in order to study these really, really small microbes, we need to use microscopes to allow us to study them. Now. Later in our course we'll talk a lot more about microscopes. But for now we're going to focus more on this term microbiology. And so the term microbiology can actually be defined simply by looking at its roots. And so notice that the prefix micro, which is a prefix found in microbiology, is a prefix that means small. And so in the field of microbiology, the main focus is really, really small organisms and infectious agents. Okay now the word biology is a word that means the scientific study of life. And so the main focus of microbiologists is to study living organisms that are simply really, really, really small. Now it's also important to note that although microbiologists mainly focused on living organisms that are really, really small, they sometimes also study non living infectious agents that are really, really small. And that's because these non living infectious agents like viruses, for example, can infect and in effect uh organisms that are really, really small. And so we'll be able to talk more about this idea as we move forward in our course. Now it turns out that the smallest and the most basic or the most fundamental unit of life is actually the cell. And so moving forward in our course, we're going to talk a lot about the structure of cells and the functions of cells. And we'll also talk about many different types of cells as well. Now the term organism is a really broad term because the term organism can refer to any individual form of life. And so the term organism could be referring to a uni cellular organism or an organism made of only one single cell. Or the term organism could be referring to a multi cellular organism that is made up of multiple cells. Now the term micro organism again has that route or that prefix micro, which we already said is a prefix that means small. And so microorganism is simply an organism, a living organism that is simply too small to be seen with the naked eye alone. And so once again we need the aid of microscopes in order to visualize and study these microorganisms, these organisms that are really, really small. Okay now notice that down below were also defining microbes again for a second time, even though we technically already defined it up above. And the reason for that is because sometimes the term microorganism is used in a synonymous way to the word microbes. However, technically these are not synonyms. Microorganism and microbes have subtle differences in their definitions. And so here we put these two definitions, side by side to help you better understand how these two terms are similar but also how they are different. And so once again, microorganisms is referring to living organisms that are really, really small. Now the term microbes includes microorganisms, so it also refers to living organisms that are really, really small. However, the term microbes also is referring to non living infectious agents such as viruses, for example, that are also too small to be seen by the naked eye. And so um microbes includes microorganisms, but it also includes non living infectious agents, whereas the term microorganisms only is referring to living organisms but does not refer to non living infectious agents. And so hopefully that can help you better understand the differences between those two key terms. And so if we take a look at our image down below notice on the left hand side, we're showing you a human being a microbiologist if you will, which is a living organism. Of course, more specifically, this human is going to be a multi cellular organism because humans are made up of many cells, trillions and trillions of cells. Now notice that this microbiologists in order to study microbes which are really, really small. Uh the microbiologist need to use a microscope and again, we'll talk a lot more about microscopes later in our course. But the microscopes allow the scientists to visualize the microbes which are really, really small. And once again, the term microbes is going to include really, really small microorganisms, living microorganisms uh such as a bacterium that you can see right here. This is one single celled bacteria. And microbes also includes some non living infectious agents, such as viruses, for example, which are lacking many of the characteristics of life. And so are generally not considered alive, but they are non living infectious agents. And sometimes they are still studied by microbiologists because these non living infectious agents can sometimes affect uh cells living microorganisms. And so over here, on the right hand side, we're showing you a collage here of many different images of the microbial world, all of the mic or many of the microbes that exist, such as viruses and specific type of arcadia and virus, other viruses and bacteria and single celled organisms. And uh these are called bacteria. Fage is And so we'll talk a lot about the microbial world, basically the different types of microbes, microorganisms and non living infectious agents as we move forward in our course. But for now, this year concludes our introduction to microbiology and again, we'll be able to learn a lot more as we move forward. So I'll see you all in our next video.
Which of these is considered a microbe but NOT a microorganism?
SARS-CoV-2 (Covid-19 virus).
Escherichia coli bacterium
Necator americanus (a hookworm).
Dinobryon divergens (Golden Algae).
None of the above, all are microorganisms.
Which of these are characteristics of microorganisms?
Microorganisms are so small they cannot be seen with the naked eye.
Microorganisms can be multicellular or unicellular.
Microorganisms include the smallest units of life and non-living infectious agents.
Microorganisms can have DNA or RNA as their genetic material.
A and B are correct.
C and D are correct.
All of the above are characteristics of microorganisms.
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in this video, we're going to focus on the discovery of microorganisms. And so it turns out that humans were not always aware that microorganisms even existed, let alone, that they exist in pretty much every conceivable environment all around us. And so it turns out that the existence of microorganisms was actually discovered just a couple 100 years ago, during the time period between 1665 and 1674. And so in 1665, an English microscopy ist of the name Robert Hooke was actually the very first person to visualize and depict or create a drawing of a micro organism. More specifically, robert Hooke described a common bread mold known as music or as a microscopic awhile mushroom. And so if you take a look at the image down below, over here, on the left hand side, there's a little portrait of Robert Hooke who lived from 1635 to 1703. And here is an image of hooks microscope that he used to visualize the very first microorganism and depict the very first microorganism. And so over here on the right is robert Hook's drawing of the bread mold. His depiction of the bread mold Now in 1670 for just a few years later, another scientist really a Dutch merchant of the name of Antony van Leeuwenhoek uh analyzed a drop of lake water with a microscope and he saw microbes many different types of microbes other than just these microscopic, all mushrooms. And so antony van Leeuwenhoek he described and depicted uh protozoa which are these very small eukaryotic organisms. We'll talk about them more later in our course. And he also depicted bacteria, which are these very small pro carry attic organisms. Again, we'll talk more about those later in our course. And so antony van Leeuwenhoek, he depicted a whole different set of microorganisms and he called these microorganisms and molecules, which really just is the word meaning little animals. And so if you take a look at the image down below, you can see a portrait of antony van Leeuwenhoek over here who lived from 16 32 to 17 23. And here is an image of antony van Leeuwenhoek microscope that he used to visualize the protozoa and bacteria. And so here is an image of the depictions uh that antony van Leeuwenhoek created when he observed that lake water and again he called them anna molecules or little animals. And so you can see that there are many different types of protozoa and bacteria that he had drawn in his images. And so, robert Hooke, he observed a microscopic all mushroom, a common bread mold, which is a little bit larger than these other protozoa and bacteria or however they're still at the microscopic level. But uh regardless, Hook and Lavon Hook are both equally deserving. They both deserve equal credit for revealing the microbial world. And so again, uh due to robert hook and Antoni van Lavon hooks discoveries, they revealed that there was an entire microbial world of really, really small organisms and infectious agents that were all around us. And so this year concludes our lesson on discovering microorganisms and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video.
Antonie van Leeuwenhoek observed microorganisms under his microscope and called them “animalicules” (little animals). Which microorganisms did he observe?
Algae and bacteria.
Bacteria and protozoa.
Bacteria and viruses.
Protozoa and viruses.
He observed all of the above.
Robert Hook’s and Antonie van Leeuwenhoek’s microscopes were not powerful enough to observe: