in this video, we're going to introduce the scientific method. And so here's a question that maybe some of you guys have never thought of before. And it's asking How can you possibly trust the information that you learn from your science textbook? Well, the answer to that question is, you can trust the information in your science textbook because the information in your textbook has been subjected to the scientific method. So then the question becomes, well, what in the world is this scientific method? Well, the scientific method is defined as a procedure that is used by scientist to answer questions, test ideas and gain scientific knowledge. And so this scientific knowledge that has been subjected to the scientific method is going to make its way into your textbooks so that you can learn from it and you can trust it. And so the scientific method is a Siris of steps that will talk about down below in our image. But the scientific method always starts with an observation and a question. And so if we take a look at our image down below once again, what we have are the seven steps here to the scientific method And so again, the scientific method always starts with an observation and a question. And so the very first step is going to make is going to be to make an observation, and the second step will be to ask a question. Now we're going to apply the scientific method to an example that might be a little bit more relatable for you all. And so let's imagine that one night some evening you're studying for your biology test, but then you realize that the desk lamp does not work. And so here notice that we have your desk and we've got the lamp here on your desk and you're observing that the desk lamp does not work, so that would be your observation. After you've made your observation, you would move onto the second step of the scientific method, which would be toe ask a question. And so, for example, your question might be why doesn't the lamp work? After the second step, you would move on to the third step of the scientific method, which would be to formulate a hypothesis and to make a prediction as Thio, why your lamp might not be working and in our next lesson. Video. We're going to distinguish between hypothesis and prediction, but for now, for simplicity sake, let's just say that the hypothesis is an explanation for your question. And so why doesn't the lamp work? You might think that it's not working because the bulb in the lamp is just simply loose. And really, all you need to do is just screw in that light bulb just a little bit tighter, and maybe it will start working. So after you formulated your hypothesis and made your prediction, you would move on to the fourth step of the scientific method, which is to design and conduct an experiment. And the experiment in your example here might be to just screw in the light bulb a little bit tighter. You just go in and you screw that light bulb tighter. After the fourth step, you would move on to the fifth step of the scientific method, which is to collect and interpret the data from your experiment. And so this would be like checking to see if your lamp actually works after you've screwed in the light bulb a little bit tighter. After the fifth step, you would move on to the sixth step of the scientific method, which is to draw conclusions. And when you're drawing conclusions, you're basically asking, Should we accept or reject the original hypothesis that you made over here? So let's say that you screwed in your light bulb a little bit tighter. You check to see if it worked, and then all of a sudden it did work. At that point, you would accept your hypothesis and move on to the last step here of the scientific method, which is Step number seven, which is peer review and publish by peer Review. What this means is that you would get one of your peers, maybe your parents or one of your classmates to check your entire scientific method process, and they would check it for errors and mistakes and things like that. Now, if your peers review your process and they approve of it, then you can go on to publishing your data, your results and your conclusions, and you could go ahead and publish primary literature. And really, all of the information in your textbook comes directly from published primary literature that has undergone this scientific method multiple times. Now, let's say, for example, that you went through this process here, you screwed in your light bulb a little bit tighter. You check to see if your lamp work, but then you realize that it did not actually worked. In that case, you would need to reject your original hypothesis. And if you reject the original hypothesis, you would not go to Step seven. Instead, you would go on to repeat the entire process so it would be a cycled. So then you would have to make an observation. Maybe it's the same observation you would ask a question. Maybe it's the same question, but then you would need to formulate a new hypothesis and make a new prediction, and that would require the design and conduction of a new experiment. And of course, you would repeat this entire process over and over and over until you're capable of accepting your original hypothesis and publishing your information. And so this here is really the scientific method here, and that concludes our introduction to the scientific method. So in our next video, we're going to distinguish between predictions, hypotheses and theories. So I'll see you guys in that video
Predictions, Hypotheses, & Theories
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in this video, we're going to distinguish between predictions, hypotheses and theories. And so a prediction is really just defined as an expected outcome of an event that can either be correct or incorrect. And so a prediction is on Lee going to address the answer to the question. What will happen? And so, for example, I could make a prediction that tomorrow it will rain Now. Tomorrow it will either rain or it will not rain. And so my prediction of this expected outcome of an event will either be will either be correct or incorrect. Uh, now, the hypothesis, on the other hand, is a little bit different now. The hypothesis is defined as a proposed and testable explanation for an observation, and so the explanation here is very, very key. And so, ah, very well designed hypothesis is going to address the answers to two questions. What will happen but also why it will happen and why. Here is really where this explanation comes into the play and so notice that because it answers the same question, what will happen as the prediction? A really well structured hypothesis, a really good hypothesis will actually include a prediction And so, for example, if we go back to that rain example, I could make a hypothesis that tomorrow it will rain because I pointed to the sky Now the hypothesis is not always going to be true. It might not be true that if I point to the sky, it's going to rain. But the hypothesis will always be testable and it will always include an explanation. The why I'm sorry, the what will happen and why it will happen. So it will rain tomorrow because I pointed to the sky. The because part is answering why it will happen now. The last term here. The theory is really just defined as a testable and broad hypothesis of many observation supported by a large body of evidence. And so really, the theory is a hypothesis. So in many ways it's going thio have ah lot of similarity, similarities to the hypothesis and the key terms here for theory that distinguish the theory from the hypothesis eyes the word broad, uh, the word many and the word large. And so the theory is really just ah hypothesis at a much larger scale. And so an example of the theory as it goes with that rain explanation is every single time I point to the sky, it will rain the next day, and so that is a much larger scale. That explains why it will happen and what will happen now down below. What we have is another example that we can apply these three terms of prediction, hypothesis and theory, and so over here on the left were setting up the scenario. And so we're starting the scientific method with an observation and a question, And the observation here in this example is that the lawnmower won't start, and so you can see here we have the lawnmower and you can see that it's not starting. So that's the observation. And the question would be, why doesn't the lawnmower start now? From this question, we could really formulate these three different terms. Prediction. An example of a prediction would be the lawnmower will start if you add gas. Now remember, the prediction is an expected outcome of an event. It can either be correct or incorrect. And so once again, it says, uh, for the prediction. The lawnmower will start if you add gas. Now, if we add gas either the lawnmower will start or the lawnmower will not start. So the prediction can either be correct or incorrect. And so you can see here that if we add gas, uh, to the lawnmower, uh, predicting that it will start is going to be a prediction. Now, over here in the second block Over here, what we have is the hypothesis. Now, once again, the hypothesis is going to be a proposed and testable explanation for the observation. So not only will answer the question to what will happen, but it will also answer the question, too. Why it will happen. So, for example, here what we're looking at as it's saying, the lawnmower stop working because it ran out of gas. So if you add gas, then it will start working. And so what you'll notice is that it does answer the question to what will happen if we add gas. It will start working. But it also answers the question, too. Why it will happen with this because here it ran out of gas. And so the because is answering why it will happen. And the prediction is answering what will happen and so you can see here in our image that this little gas meter is answering the why it will happen part because the gas meters on empty on. So if we add gas, then we predict it will start working now moving on to this third slot over here. What we have is, of course, the theory and the theory once again is pretty much a hypothesis. However, it's at a much broader in larger scale. It's going to be of many observations and supported by a large body of evidence. And so notice. Now, instead of having one lawnmower, we're showing you multiple lawnmowers. We're still explaining why uh, it will happen on were also still explaining what will happen and so notice that it's saying for the theory, all lawnmowers stopped working when they run out of gas, and so you can see the why is because they run out of gas. Uh, the what will happen, um, is going to be. When you add the gas to it, it will start working. And so the theory once again, is going to be at a much broader scale, and that's really the main point here. Now, here at the bottom, we have a note that you guys should take into account here, and that is the fact that technically, hypotheses and theories can never be proven correct. But they can always be falsified, which means they could be proven incorrect. And so that is why you must either accept or reject the hypothesis. But you can never say that the hypothesis is true or correct. In the same goes with the theory on DSO, There are many, many different theories that we're going to introduce here that applied to biology, and once again it's important to keep in mind that they can never be proven correct. But there can be many observations in a large body of evidence that supports that they could be true. But in the future it is possible, and it is always going to be possible that they can be falsified or proven incorrect. And so this year concludes our lesson to distinguishing these three terms. Predictions, hypotheses and theories and moving forward will be able to get a little bit of practice. So I'll see you guys in our next video
Scientific Method Example 1
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all right. So here we have an example problem that says a scientist observed a new phenomenon and wonders how it happens What is the next step in their study? And we've got these five potential answer options down below. And so what we need to realize is that when the scientists observes the new phenomenon and then wonders how it happens, this is really telling us that the first two steps of the scientific method have been completed. And so the observation step and the question step have both been completed already. And so really, what we're looking for here in this, uh, problem is the next step, which would be the third step of the scientific method. And so when we consider that, of course, we know that the third step is going to be to create or formulate the hypothesis on. So that would be to, um, essentially essentially hypothesized on DSO Option E here is going to be the correct answer for the next step. Observe has already happened. Experiment does not take place until after the hypothesis has been generated. So that won't be the next one. Uh, designed the experiment once again. That is not going to happen until after the hypothesis has been created, and then peer review is one of the last steps of the process. And so, once again, option E hypothesize is the correct answer here, and that concludes this example. So I'll see you guys in our next video.
Which of the following shows the best order of steps of the scientific method?
A scientist observes that even after sterilizing a broth, cells reappear in the broth over time. The scientist then asks:“Why do cells reappear in the broth after sterilization?” and designs/conducts an experiment. Considering this, appropriately label each of the following blanks as either a “prediction, hypothesis or theory.”
________________:Cells will only appear in the broth exposed to a source of preexisting cells.
________________:Cells appear only when preexisting cells grow & divide; therefore, cells only appear in exposed broths.
________________:All organisms consist of cells & all cells come from preexisting cells.
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Basic Theories of Biology
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So now that we've introduced the term theory in our previous lesson videos here in this video, we're going to talk about some basic theories of biology. And so really, there are three basic theories of biology that your professors tend to want you all to know. And so notice down below, in this table, we're going to show you each of these three theories and the concept that they apply to. And so the very first basic theory of biology that you should know is the cell theory. And the cell theory is pretty much saying that all living organisms are made up of cells and all cells come from pre existing cells. And so here we have a little image of a cell. Now, once again recall that theories are really just broad hypotheses, and so we can tell that it's broad here because it includes this word all Now, the second theory that you should be familiar with is the home eo Stasis theory and the home eo stays. Theory pretty much says that all living organisms are going to be able to maintain a relatively consistent internal environment, and so here what we're showing you is a little picture of a person sweating in the hot sun, since sweating is a mechanism that helps to maintain Homo Stasis. But really, all living organisms had this ability to maintain relatively consistent internal environments. And once again we can tell that this is broad because it includes the word all again. Now the third and final basic theory of biology that you should be familiar with is the theory of evolution. Now the theory of evolution does not say that evolution itself is a theory. Instead, the theory of evolution says that all living organisms evolved from a single common ancestor. And so here what we have is a little image that's used commonly to represent evolution. But the idea here is that once again, theories can never be proven to be true. Instead, there's, ah, large body of evidence that supports the theory. But once again, the theories will always remain falsify a bill which means that they can be proven to be false, moving forward in the future. But once again, they will never be proven to be true. And so there is quite a lot of evidence that suggests on supports all three of these theories. But for now, this here concludes the basic theories of biology that you should be familiar with, and I'll see you guys in our next video.
Which of the following statements about the cell theory is false?
All living organisms are made of cells.
All cells arise spontaneously.
Cells are the basic structural & functional unit of life.