Can I Pass A High School Biology Exam 20 Years Later? | Ft. @MissEstruchBiology

Hello maths fans. I'm Dr. Tom Crawford, a mathematician at the University of Oxford and the University of Cambridge. But today I'm not doing maths. For some reason, I am doing biology, which of course means I need some help. Now, fortunately, I have found the perfect teacher. This is Miss Est who runs the YouTube channel Miss Est Biology. — That's right. — And you used to be a teacher. — I did. I was a teacher for 16 years. — I told you. perfect person to help me try and figure out GCSE biology. So, we're doing GCSE because I didn't do A level. — Okay. — So, I know I think you said Alevel is like usually your specialtity. — It's my remit, but I do GCSE as well. — Okay. Good. Told you. Perfect teacher. And because I didn't do Alevel, I quite frankly have not thought about biology in a academic context for 20 years. — Yeah. Of course, because you were like — I was like academics key there. You've definitely thought about biology a lot, but not in terms of exam questions. — No. So, so I think I hope I have a my life experience has taught me a lot about let's say at least like human biology, you know, like I do a lot of exercise, so I have an idea around nutrition, — muscles, etc. I'm hoping that will help. I don't know. — Fingers crossed there are some link to that. — Okay, good, good, good. So, so you've brought along just a whole subset of questions, haven't you? Really? I have and I actually asked my audience for some tough topic suggestions. I told them that you are going to be grilled with some biology. So, I'm afraid they have picked out some of the hardest topics that we're going to put through. — Thanks everyone. I Yeah, I'm possibly meeting some of you for the first time here, right? Cuz you're biology. I'm math. But thanks. Really appreciate that. — So, the first question was the most commonly suggested one. We're going in tough. It is blood glucose control. — Okay. I definitely know what blood is. — Good. — I understand what glucose is. — Control. I'm worried. Um — I think you'll at least remember the two hormones. Whether you remember what they do, — okay, — is another matter. All right. — So, we'll see. But I can there's a few tricks I can give you to help work it out. — Okay. The human body must maintain blood glucose concentration within a narrow range. Happy. This regulation is achieved through hormones released by the pancreas acting as a homeostatic mechanism. Right. Name the organ that monitors blood glucose concentration and releases hormones to control it. Is that not just the pancreas? Because it told me in the question. — Yes. So you had a little bit of an easy one to start with. Can you read the question and do you understand it? So yes, the pancreas. — Okay. I think in my head when you said glucose, I was like this is something to do with the pancreas. before I read the question. So I I know I can say what I want after I've already read it, but anyway, when blood Okay, puppy. When blood glucose concentration rises above the normal level, a hormone is released. Right. Name the hormone and describe in detail the four marks. We are not starting easy. — Bloody hell. — Well, the first one was a bit of a gift and now it's like right in detail. how it causes blood glucose concentration to return to normal. — Okay, I'm gonna start with what I think I can remember. — Okay, — which is I think the hormone is insulin. — That's one mark straight away. So, that's right. So, um I will just write the hormone. — I'm not going to write the hormone that controls blood. I'm just write the hormone is insulin. Yeah, — right. The hormone is insulin. Okay, good. That's good to know. So, I've got one of the four in detail how it causes the concentration to return to normal. So, I'm going to hazard a guess and this is again I'm going to try and use my what I'm calling my mathematician's logic — like it — if is this is when it's high. — Yeah. — Okay. It's above, right? So, it's you've got too much glucose. So, if you release insulin to help bring it down, I'm going to guess that the insulin must somehow I don't know whether it's reacting or it physically bonds to the glucose. I'm not sure about that stuff, but it must do something. It must like latch onto the glucose — to turn it into something that isn't glucose. — Yeah. So, particularly that last bit is key. — Yeah. Is it a reaction or is it not as — it's a cascade of reactions happening but that's going beyond GCSE but the key here is yes is a reaction because glucose is being converted into something else — that is a store of glucose and it's insoluble — okay so you've got too much glucose — the insulin turns it into something it's not like fat is it — no it's this topic is full of gwords Right. — So, if in doubt, it begins with the letter G.

— Okay. — Gly glycogen. — Yes. — I don't think I know what glycogen is, but I was like, this is Okay. Right. So, — we've missed a few steps, though. So, put that bullet point like four. — Okay. Okay. So, bullet point four is So, is it the insulin causes a cascade of reactions turning — into glycogen? — Okay. So, I'll just write cascade of I'm if you you're telling me this is worth the mark in my bullet point form, I'm going to write bullet point form. Cascade of reactions — just for the you should all write full sentences, right? — Well, yeah, you can do full sentences, but you can actually bullet point for GCSE as well. — That's good to know. — It has to make sense though. You can't just like the odd word, but yeah, that would be fine. — Extain that turn the excess glucose into glycogen. And in fact, it's just that last bit of the sentence that would get you the mark. Excess glucose converted to glycogen. — Okay? — But that doesn't happen in the blood. So this is — the insulin. There's actually going to be a mark for saying where that insulin is released from and where it's going to be from the pancreas. And then it's transported in something. And this something is all hormones are transported in this. — Okay. So insulin is released from the pancreas. Okay. which is again part a that they told me the question like this. Okay. So insulin released from the pancreas. — Um and then you want me to think about how it's then transported. — Yeah. — Okay. But it's transported within the blood inside something in the blood. — That's actually the answer. It's transported in the blood. — Oh okay. Reason of angrius. Okay. So Oh wow. Okay. So reason transported in the blood. But where too do you know which organ that this final stage is going to happen inside of the cells of? — Okay, I want to say liver because it feels like a liver based. — Yeah. — Okay. Go. — Right. So, — you're making [snorts] a lot of GCSE students feel horrible right now. Like we took years learning this. — Yeah. — Well, to be fair, you did do GCSE just Yeah. Yeah. And I do have a good memory. I will admit that it's I like it. I have a good memory. I can recall random things. — Okay. Cuz that's why glycogen was in there. I haven't said the word glycogen for 20 years, but my brain was like when you said a G, I was like it's — it's got to be. — Okay. So, I'm just going to get this straight in my own head. — We've got um Okay. So, you're like you register that this glucose is too high. The pancreas releases the insulin — and that's two marks from its insulin release from the pancreas and then transported in the blood would be — okay. And then it's transported in the blood. Um, and then once it's in the blood, it just within the blood, it then just causes these reactions — or it has to get to. — So this is where there's a bit of a gap between GCSE and A level. So at GCSE, — you'd be fine. So transported in the blood to the liver. — Oh, okay. So you're kind of thinking of it as going to the liver and that's where the conversion happens. — happens inside of the liver cells. — Understood? Yeah. For a level, you need to know a bit more. Like there's receptors, it binds to that cascade of reaction. — Yeah. Yeah. Yeah. I went in with the way over the top stuff. — Straight to A. — Yeah. Okay. Transporting the blood to the liver. Um and then in the liver, the this reaction glycogen. — Amazing. And then would you need to say like stored in the liver or — um [sighs and gasps] — it's not wrong to say that. That is correct. So glycogen is a store of glucose in the liver cells. — Okay, — there may or may not be an extra mark for that. For four marker, probably not. But when it's a six mark questions, — they might want that additional — that extra. — And a question like this could be two, four, six. — Yeah. — And that's just about understanding the level of explanation required. — Yeah. And sometimes they might ask you to describe a particular stage of the process only as well. — Right. Awesome. That was fun. I appreciate I appreciate. Yeah. No, it is. I agree. I appreciated the the little hints and tips, right? Let's see. We're not finished yet, have we? — So, that's a — far from it. — Oh, yeah. Far from it. Wow. Okay. Part C. Glucagon. Okay. That sounds like a Pokémon. Literally Glucagon. — I would love to know what Glucagon Well, I know what Glucugon's powers would be if it was a Pokémon. Oh, that'd be such a cool Pokémon. — Can we somehow have people watching this like send us drawings of Glucagon? Whatever. Whenever you're I'm picturing Glucagon as a Pokemon. I would love to see what other people I can't draw, so I'm not going to try. But other people who are watching this who can draw, — please send me a picture of Glucagon as a Pokemon. Okay. Um is released when blood glucose concentration falls below. Oh, so this is the other one. — This is the opposite. — So now you're low, right? Okay. So I'm just going to make a note to myself uh that we're now on low glucose. Okay. — Best way to remember this as well. Glucagon. When the glucose is gone, you release glucagon. Amazing.

— The Pokémon have catchphrases because that would totally be their catchphrase. — I mean, yeah, I mean, they say things and yeah, you know, got to catch them all is the is the whole thing, but Okay. Right. So, glucagon is gone. Yeah. Nice. Involve a normal level. Describe the role of glucagon in restoring blood glucose to normal. Include the name of the process by which stored carbohydrate is converted back. Okay, I'm drawing more blanks this time than I did before, but I'm going to break it down. — I was going to say I think you will be fine with this one if you look at your previous answer because this is the reverse. — Yeah. — Of this. — Thank you. That's a very helpful. I'm going to say this throughout the video. I knew I was in good hands. Right. Okay. Um glucose. Okay. Include the name of the process which stored carbohydrate is converted back to glucose. So I'm going to guess then. So, it's already told me that glucagon is released. Do I need to say where it's released from? — If in doubt, I put it down. It's three marks. I would put it down. — Okay. So, now do I have a clue? — Is it going to be the pancreas again? — Yeah. — Okay. It just feels like if it's — if you were to have an organ that's controlling something, it feels like it would do both. It feels sensible to me again. I think that's my mathematical logic kicking in, right? Because I definitely don't remember. — Glucagon is released from the pancreas. Okay. Released from pancreas. Um so therefore it's going to be transported in the blood. — It's going to go therefore to the liver. — Yeah. I reckon all of that would be one mark here because — okay we've kind of already said — the part above. We've said it above. Yeah. But okay. So I'm just I'm like picturing in my head. Right. So pancreas things turns in the blood gets the liver. Now liver has the store. — The stored carbohydrate is in the liver. So once it's in the liver, um this then I'm going to say this then initiates the conversion. Do I need to say it's um it's glycogen or can I just say stored carbohydrate? — Glycogen. — You would say initiates the conversion of glycogen — back into glucose. — Yeah, — I'm going to hazard a guess because that's the thing we don't have enough of. And then so I'm guessing that's two. And the third mark is going to be the name of this process, right? Okay. Back into glucose via the process of now the process of you told me think of a word beginning with G. — Begins with G. — I'm going to remember that. Okay. — And we're breaking down glycolysis or something. Is it? — No, you're going to respiration there, — right? Okay. — But — glycogenis, — it's pretty much that, but they put an O in between the two words. So glycogen olyis, but glycogenolysis is how we say it, but it's glycogen osis. — It's spelled like l i s i s. — L y — Yeah. Okay. Glycogen. — So glycogenolysis or glycogen. — Yeah. So I wasn't a million miles away with like glyolysis or whatever I was guessing. — Exactly. So glycogen at the end. — Okay. — This one here for GCC probably would be okay. But where you've got is converted to glycogen uh sorry glucose. In the question it said converted to glucose. So might want you to say broken down so you know what that conversion actually is rather than using the same word. — Okay. No, I like that. The breakdown — initiates the breakdown of glycogen — um back into glucose. It wouldn't be via the pancreas this time. — Via the process. — Oh by the process. My writing is terrible. It's a math. None of us have good handwriting. — I don't know. Mine's pretty bad, [clears throat] too. — Okay. Right. The pro Maybe it's a teacher thing. — It's a teacher thing. — Okay. Right. — There we go. — Okay. Awesome. I not in a million years would I have got that word, but I appreciate you. — Difficulty with the students, but the key word. Yeah. No, I wouldn't have had that at all. — Anything that's to do with glucose starts gluco. Anything to do with glycogen starts glyco. and then try and work it out from whether it's LIS splitting, genesis making. — Oh, okay. — Then you can kind of work, — right? Yeah. Yeah, that's a more common one. But lis Okay, cool. This is how I feel like maybe this will help me on further questions. We will see. But — definitely in quizzes. — Ah, I do occasionally do a pub quiz. So, and I've we've been finishing second a lot recently, so maybe I'm missing this. — Right. And there's more. Okay. Of course, there's a six marker compare. Oh, man. And there's no way I'm going to be able to do this. Compare type 1 diabetes and type two diabetes. Again, thank you everyone for this question. Type 1 diabetes and type two diabetes. In your answer, refer to the cause of each condition, how each condition can be detected, and treated or managed. — Right. Okay. So — now you are allowed to bullet point your

answers. — Yeah, — this is a six marker. I'd be splitting into two marks per each of those instructions. — Okay. — So they said the cause. So what causes type one, type two? — Yeah. — Um — I'm going to do like a little table issue. I'm going to just — do this for myself. Okay. The causes, how each condition can be detected. So I'm going to write detection there. Um and how each condition can be treated or managed. Right? So let's call it treatment. — And also with the six markers, they often don't require you to do six bullet points. So the six markers are normally like best fit. So they'll say they have at least two descriptions and an explanation if that was relevant from this list. So we'll probably get five bullet points. It'll be two for that. They're detected in the same way and then the treatment. — Okay. Right. Gotcha. — It's different for that. — Know. Yeah. Okay. Now type two I know is the common one. — I think — you probably hear about that one a lot more in the media. — Yeah. Okay. Okay. So therefore that makes me think that one is associated with uh obesity. obesity and all of those other kind of health issues related to bad diet. So, I'm thinking a bad diet is going to mean you're eating too much sugar. So, that's going to be I'm guessing then p type two — the cause must be um high glucose intake. — Yeah. But you don't actually even need that level of detail. Obesity would get you the mark. Okay. — Um for GCSE y — um and diet, lifestyle. — Okay. Yeah. Fabulous. Obesity, poor diet. Okay, cool. — Obesity would be the key one there, — right? Fabulous. Okay, so then the other one, — generally speaking, if something's not caused by your environment, what's it going to be caused by? — I was thinking, is this the one like genetic basically? Because it doesn't feel like could you get it from just not eating enough sugar like — No, — it is. Okay. — No. So, yeah, it's an autoimmune disease. So, — so genetic. — Fabulous. Okay. Like it. Right. Um, detection. Um, so the detection then I can tell you some of the symptoms if that doesn't count though, does it? Um, would it be a case of doing a blood test and measuring levels? Would that count? — That would count. You can do like um finger prick test. — Okay. Yeah, — you can also test urine because if you're diabetic, you're not meant to have glucose in your urine. So, you can test to see if there's glucose in the urine. — Okay. Ag fingerprint test or uh urine test for glucose. Cool. And you're happy enough that I am getting marks so far for cause and detection. — Yeah, that's fine. — Brilliant. Like this. Uh it's good. Now I can check immediately like reassure me that what I'm writing is okay. — Imagine you've had that in the exam. It'd be lovely, wouldn't it? Like no, try again. — Hire to like sit next to someone in the exam. — I do get asked that a lot, but no. where like um you just need the Harry Potter invisibility quote. — That would be good. Yeah. — Whispered. — Somehow whisper it. Yeah, — because you know I wrote the answer. I didn't. True. — You did help a lot. Um okay. Treatment. Right. So treatment is going to be um you need uh insulin injections if you have — right. Would that count for type two? One possible treatment there would be — you can do that. Yeah. For type two. — Okay. Yeah. Um, I'm guessing obviously like do exercise and be healthier is also does that count? — So that's the main one because — if you can manage it without having to have injections. — It did say manage treatment actually. Okay. — Then it's going to be better. — Okay. So I just say like exercise or — lose weight. Yeah. Cool. Okay. Now type one. So type one means you don't have enough. So that means you're going to need the thing that we wrote up here. It means you are needing glucagon. So would you therefore need somehow to stimulate your body to produce glucagon? — Why did you jump to the glucagon? — Because glucagon ah you're right. Okay. Cuz that's breaking down. But if you don't have the store to break down is useless. — I see. So it's literally just take glucose. — Well, you can do that. But the treatment is — eat jelly babies. You have low blood sugar. — If you're at crisis point, then yes, but to manage it, it would be insulin injections as well. So for both of them, so for type 1 diabetes, it's an autoimmune disease. So your own immune system is destroying the cells in the pancreas that produce insulin. — Ah, — so you either don't produce any insulin or not enough. — I see. type two diabetes. You still produce insulin, but your cells stop responding to it. So that's why you can have insulin injections, but it's not

perfect. You're just not responding. — So type one is actually the insulin injections, but the insulin is — I thought the insulin was basically when you had too much glucose in your blood. — Yes. So — So type one is still having too much glucose. — Yeah, it's still the same for both of them. — I thought type one was not having enough glucose. — Ah, no. So for both of them it's linked to um insulin. — It's like bad management of glucose levels. — But the reason that sometimes gets confused is because if you're not producing insulin, — you're not making glycogen stores. — Yeah. — So then if you don't eat for a long period of time, even though you're releasing glucagon, there's no stores to break down and that's why you can then um go into a coma or something because you don't have any stores to rely on until you eat again. — I see. Okay. So, that went better than I expected. — I'm very impressed. Yeah, some very good knowledge there. — Okay. Um, however, it did feel like a lot of biology. — It was quite content like theory recall heavy. — Yeah. Which is why all the viewers have picked it, no doubt. So, is there something slightly more mathsy just to give me like a light relief and then I'll come back. I'll try I promise I will try another biology, proper biology, but like just like a light relief. — I think you will love inheritance. It's my favorite topic. Yeah, there's a lot of problem solving and there are mathematical elements. So, I think you're going to like this one. — Okay. Jeans, — alals, alals. — Yeah, alals. — I mean, people say it differently. Alil. I say al people say different things. — Okay. Define the following terms. — I mean, that's not really jumping straight into maths. It is definitely a definition here, but let's see. — This is an interesting definition of a bath question. Um, okay. So I know what dominant and recessive means. I'm going to start there. — Yeah. — Okay. So dominant means Okay. No. So is an alo which I'm going to apparently is how I'm saying it. So is that the characteristic that can be inherited? — Yes. — Sort of what I'm thinking about the definition. So you've got the correct concept there. — Right. So it's like this is like the classic blue eyes and brown eyes. — Yes. So those are alals. — Okay. The gene would be for eye color and you can have the alil blue brown. I mean you technically can't but that's an example. — So the alle is the the variant of the gene. — Yeah. So different versions of a gene. That's a definition. — Perfect. Okay. Cool. Cool. Right. I wouldn't have known the technical as usual, but I Yeah. Okay. All right. I'm convincing myself. I remember some things different versions. Okay. Awesome. Now the dominant one that means that um if you just have one of them then that characteristic will prevail. — Yeah. — Is that pretty much how you would — Yeah. So um it's the al that's always expressed in the phenotype. — Okay. Wow. Way more technical than what I just said. — Well, you said it is always prevail basically mean it's always going to be expressed. Phenotype is what is actually displayed what you — So this is funny. al expressed uh that's always expressed in the phenotype. Yeah, I do remember this phenotype word. — I think you would have still got it though for saying you only need one of those alals for it to be expressed. — Yeah, because that's the thing the same thing. — Recessive means you need the twoactive means will only be expressed when uh two copies are present. Yeah, that okay. So only expressed when two both from both parents when two copies present. Okay. — And now you have that reminder. It leads you nicely into the maths elements. — I'm excited. All right. Brown eye color. Oh, here we go. I didn't even read it. Right. It's the classic inheritance thing, right? Blue and brown. Okay. Brown eye color is dominant over blue. A man who is hetererozygous, that's a biology word for eye color, and a woman who is also hetererozygous, so heterero is meaning they're different. Yes, understood. Yep. — Have children together. Completely pun it square below to show all possible genotypes of their children. Right. Magic. I can do this. — Um, so I'm going to just draw out my less clear version of the same thing. So, we've got capital B. I like the capital and the lower case to emphasize the dominant one actually is quite nice. — Yeah. — Okay. So, we have two dominants. Then we are definitely brown all day long. — And then we just have that one's brown because you've got one of the brown so it dominates. This one has one And only if you get the blue from both do you end up with blue. And that's my three marks. or have I got — it's correct biology but this will be a matter of not remembering what you have to include in a pet square

— okay the pet square below to show all possible gen — genotypes so you've written phenotypes which you do need but you need the genotype as well — so would that be so is this me saying brown but it's BB — yes — is that what they want and here they want brown but it's — capital B lowerase B — this is also the same — does the order matter — no No. Okay. And then this is blue because there's two. — There we go. — Right. Okay. Now, that's helpful to know. Yes. In my head, that was obviously how I was figuring it out, but as I was doing it, I was thinking like — jumping to the phenotype. — Do I write? Okay. So, that's just being very clear that phenotype is the brown and the blue. — Yeah. So, genotype — specific thing. — Two also get for the gene. Phenotype is what is expressed because of that genotype. — Okay. Here we go. This is an actual maths question. What is the probability that a child will have blue eyes? One out of four is one of the four options. — Yep. — Okay. What percentage of the children are predicted to be homozygous dominant, which very healthy tells me is BB. Um, so as a percentage then that's going to be 25%. — Quite straightforward math for you there, isn't it? — It is. I like this. I like this. Um, explain what is meant by natural selection. I — was going to say you've had your math break. Let's get back into it. Four marks. — All right. Yeah. Yeah. Um, and write a full biography of Charles Darwin. I mean, okay, — we're in the right place for it. There must Oh, I wonder if there is a — There probably is a copy of Origin of Species in here. Yeah. — Oh my gosh, I'm going to look for that later. — Yeah, we'll have that be my dream. Wow. — Okay. Um, same what he's meant by natural selection. I describe how it can lead to a change in the characteristics of a species over many generations. — Okay. So, natural selection, I'm going to start with what I think it means. Um, we'll see how close that is to the biological. — You're definitely in the right area because you knew it was Darwin. So, — yeah. Yeah. But I'm guessing there's no marks for that, right? It's just Okay. But natural selection is the process where um it's like survival of the fittest — in the sense of and this is I'm assuming this is going to be way too much for GCSE, but like it's random mutations occur. — Mark number one. — Okay. Good. Right. So, all right. Fine. Okay. This is helpful. Right. random mutations um occur and then the idea is that some of them will be terrible but the ones that are helpful in give you a competitive advantage — will then mean you are more likely to therefore reproduce and therefore those random mutations those new characteristics will then be passed on to your offspring and over time that very small changes accumulate into much larger changes. — Yeah. So that's it. You wouldn't get all of the marks because of the sum of the terminology. — Okay. — But that's exactly the concept and even broken down into the four points. It's just some of the words we need to tweak and add in. — So the first bullet point would just be mutations. That's what creates new alles. — That's probably a bit more A level though having to know. — Okay. I I'm happy to learn more than I need. — Right. So go to create new alals and then um Right. So we got code new alles and then the ones that give the offspring you a competitive advantage are therefore more likely to be passed on to offspring. — Yeah, there's the missing bit there is that some of those also like you said give you a competitive advantage but that means you're more likely to survive in that environment. So you need the idea of survive — the environment — in that environment. — Right. Okay. So some give and you but the competitive advantage phrase is important or — no. So we call it selective advantage but it's more again a level. — Okay. — Um but it's the concept of they're more likely to survive in that environment. — So more likely to survive in that environment. Yeah. Know I that is important. Yeah. — Because that's then why they're more likely to reproduce. — Yes. Yes. — Because they're alive. — More like to survive. You're right. Environment. Right. So, for example, the first giraffe with a slightly longer neck, right, is the classic. Could reach the taller leaves, blah blah, right? — Confused what Lamar thought. Yeah. — Uh, more likely to survive in that environment. And then is it like therefore more likely to pass them on to offspring? — Yeah. So, more like to reproduce and pass on that. — Okay. — Offspring. — Yep. I need to reproduce and pass alo to offspring. Um, and then the last bit I'm going to guess is the like accumulation over time. Yeah. Kind of concept. Is there a biological technical way I should describe that? — I think for GCC it's probably fine because like I said A level is where my head's going. So I'm just going to give you the A level. So over many generations, but I think GCC over time

would be fine. Yeah. — Over many generations that al becomes more frequent in the population — which is like I said accumulates — over many Yeah. Yeah. Okay. Yeah. Many generations. Um I'm going to put new alil. — Yeah. — Becomes more frequent. — Awesome. — Another go. Four marks done. — Okay. Didn't mind that. I do. Again, it's interesting. I'm enjoying learning like the or being reminded let's say of the the technical terms the key words that are helping to communicate it in like in a biology exam versus you know just having like the knowledge of how the process works. — That's the bit that students often find painful because — you understand it. — Yeah. — But you might get zero marks because you haven't used certain words. — Is that mean? Is that mean for certain words or — I think in some instances I do think it's mean but in other instances it hasn't actually been fully explained. So I do think you do need something a little bit extra. — Yeah. — But insisting on certain words sometimes it's a bit harsh. — Yeah. Yeah. Okay. [sighs] — Right. Another form obviously bacteria can become resistant to antibiotics. Yes. Which is bad. Explain how a population of bacteria can become resistant to an antibiotic over time using your knowledge of natural selection. Okay. So, is this just going to be more or less going through these four things, but just making it like the concrete example of the bacteria? — Okay. — So, in reality, you wouldn't actually get both of those questions in the same exam because it's assessing exactly the same thing. But this is an applied example of that one. Now, — okay. So, if I'm going to write it underneath in red to say lots of things, right? So, random mutations occur to create new alles, which means here um this is resistance to — Yeah. randomly — suddenly one particular bacteria is like ah — don't mind me penicellin you're not going to hurt me like we're good this is resistance to antibiotics — yeah so that' be your first mark instead of just say new alley it will be alil for resistance to the antibiotics — yes so competitive advantage so um so therefore which is a little mass symbol for therefore therefore um more likely to survive because not being killed by antibiotics. I don't know what Yeah. — Is it? — So, in terms of their environment, they've only got that selective advantage — to survive — if they're inside of a host that's taking antibiotics. — Yes. It's protected, let's say, from antibiotics. Okay. Yep. Um, cool. And then the third point was then more likely to reproduce. Okay. So if this particular bacteria cell is more likely to survive and like isn't affected by the antibiotics then it is able to — do you use reproduce for bacteria? — Yeah, still reproduction but um that point can stay exactly the same. — I was about to say it doesn't feel like anything specific has changed there. Right. Okay. So yeah I'll just write anything and then majoration is new al becomes more frequent. So rather than saying new alle this is just replacing this with the uh ability — to not to be harmed by antibiotics. Well I should said antibiotic resistance but really now [snorts] — the antibiotic resistance — to not be harmed by antibiotics right becomes more frequent. Amazing. Well not amazing. It's bad. We don't like this. — It's very bad. — But amazing for my understanding of the exam but it's definitely bad. — Okay. And is that it or more? — Done. We're down to the last one. — Woohoo. And is this going to be biology? biology again. — This one is pure biology. But you did say you like exercise or maybe I've invented that. Maybe you said something along those lines. — Yeah. Y — So this is respiration. — Okay. — Which is not exercise, but you respire more if you're exercising. So there's kind of a link. So you might — might have some recall here. — Okay. All right. The word Oh, yes. Here we go. He says um write the word equation — for aerobic respiration. Right? — So we are definitely breathing in oxygen and we breathe out carbon dioxide. So I know that. So let's just start there — for the viewers. I know this isn't what you meant but just to clarify breathing is not the same thing as respiration. — I know that's not what you meant. — That's fine. Yeah. such a common misconception cuz respiration is a chemical reaction, — breathing is ventilation, physically getting the air in and out, but you were thinking about, well, why do I have that there to go in and out? So, yeah. — Yes. I Yeah. Yeah. It was exactly I was just kind of from No, you make a very valid point. It is this was something I actually remember do remember my biology GCSE teacher stressing towards being like don't ever say that breathing is respiration. Exactly. Like so you are completely — teacher has taken over. So, but I was just I was thinking of it in

the sense of why do we inhale breath? — Exactly. — We want the oxygen is what's going to do the respiration and the byproduct thing we don't want is — carbon dioxide going out. Exactly. Yeah. — So, I know it's oxygen plus something — is then going to give me um carbon dioxide and something I want. — Yes. — Right. Because the carbon dioxide is the waste. — Yeah. You might mislead yourself there with it being something you want. — Right. Okay. Interesting. Um — what you want isn't actually a physical product, — right? Ah yeah. Okay. So we need oxygen for restoration. So it's got to have something to do with energy. — Yes. — Right. I feel like this is coming back to me and I was like the key thing is so is that what we are we producing energy directly? — You can't produce energy. We produce is it glucose that's then used for energy or — glucose is used and we break it down to release energy. So you can't ever actually create or destroy energy. So it can't be in the equation. — So is it oxygen plus glucose? — Yeah, that was it. Cuz yeah, you need the air that you breathe and then like the food you're eating, right, which gives you the glucose. Yeah. Yeah. It's coming back to me now. — And then that is going to release energy in that reaction. — And then Yeah. So it's like again I wouldn't write this in the exams but it's like the point is energy comes out right like — yeah and someone would do it over the arrow because it's not actually a physical product but — yes right okay and I can think about this so glucose has got oh it has carbon and hydrogen so it's water — yeah nice — I know I don't know the formula for glucose but — you don't need to know it just need the word — my level my A level chemistry brain was like there's C's and O's and H's — wait wait — oh you're going to challenge yourself yes what is the chemical formula — C6 H1206. — Woo! Yes. — Love it. — I'm going to write that down even though it didn't — just to brag. — Yeah. — Okay. Cool. Right. Yeah. Cuz that was actually how I was thinking cuz I was like, I've got oxygen. I know there's hydrogen in glucose, — so therefore CO2, — that's the carbon gone. So, — it has to be H. And I was like, it's probably water. — Yeah. — Okay. Fab. uh state two uses of the energy released during respiration in the human body. Right? So what do we need energy for? Um [sighs and gasps] we need energy to basically move can move does movement count? What makes your body move? — The muscles. — Yes. And what do muscles do to move your skeleton? — They are contracting. — Yes. So muscle contraction. — Ah right. Okay. So, right. Gotcha. So, I knew the answer wouldn't be movement. — Yeah. I think lower down it would have been like key stage three. — Okay. Yeah. — But for GTC, I want you to know muscle contraction. — It's specifically that. Okay. Cool. I'm just going to put to remind myself that I brackets, right? And then something else that you need energy for. Oh, is this just like um Okay, so your heart contracts to pump blood around the body. — So, does that count as the same thing? Okay. like powering your brain like is there a — powering your brain? So that I assume is more just respiration again. — Okay. — But yes, I suppose that then means it's releasing energy but that's for chemical reactions. — There is a process which is not diffusion because that doesn't require energy but there is another transport across membranes that does require energy. — Right? And it's how plants absorb mineral ions into the root hair cells. — Oh god. Yeah. Yeah. That's the whole like ion channel thing, isn't it? — But what's the process? The process. — Two words — of crossing membranes. So diffusion occurs because there's a concentration gradient — and it's going down the concentration gradient. So I got a load of stuff here. None here. So it moves. Oh, so is it going against the — It's going against the concentration gradient. You need energy to get — Do I know what to call that process? — Probably not. Um, — I don't know. I'm going to know it when you say it. — Well, the second word is transport. — Active transport. — Yes. — I knew you get it when you said it. Active transport. Okay, cool. Right. Gotcha. Okay. Awesome. active transport. — Okay, cool. And they would be like the sort of expected two answers. — Those are your standard two for GCSE. — I guess there are more things in theory, right? But — loads, especially at a level, there's loads more that you would have the two things. That's — which would be drilled into you if you get this question GCSE biology. This is what it means, right? Cool. Okay, — great. — Brain student sprints 100 meters as fast as possible. Go student. During

the sprint, her muscles do not receive enough oxygen and begin to I was about to say anorobic respiration. That means yeah, not enough oxygen. Crossing the finish line, her breathing rate remains elevated. Yes, that's because you don't have enough oxygen. So, you're trying to get more in. — Answer the following questions about the students sprint. Right. The word equation for anorobic respiration in human muscle cells. — Right. So, it's I'm guessing it's going to be very similar to what I've got. But, do you just — not have oxygen or do you instead use CO2? — You don't have oxygen. — So, it's just glucose is broken down. — Yeah. And it's not completely broken down. So, you're not going to get the same product. — Yeah. Yes. Because you don't have So, it's But it is Okay. Because that's just what I was trying to think about. So it's just glucose is broken down into energy is still released. It's just nowhere near as much, right? It's very inefficient, — right? So energy, but it's less, but it still does something because you can still do it. It's just not good, but not as good. — Short bursts. — Yes. Yeah. Okay. Um, right. So glucose and a C6 H1206. So, what do I expect it would break down into given we're missing the O2 that we had? So, there's going to be like less oxygen, but both of them annoyingly contain oxygen. — Maybe it's neither of those. — Right. Thank you. Helpful. Because I was about to say like Yeah. Okay. — There is still oxygen in the product though because glucose does have six oxygens in it. — Yeah. So, that's what I was trying to Yeah. But it's neither of those two. — Okay. So, you're not getting the same byproducts. So, you're getting what's like the bad thing that comes from it. You then have to like get rid of, don't you? — Yeah. It gives you cramp, muscle fatigue. — Oh god. What is it? [sighs and gasps] This is one of them where I'm going to know it as soon as — you'll definitely know when you hear it. Yeah. — Okay. So, so I'm just let think about this more practically. Okay. I'm running — I'm starting to get cramps. So, you're getting cramps because like you've not eaten a banana. You need those salts, right? So, what does glucose break down into? What could it break down into? It's got to contain Oh, is it like an acid? — It is an acid. Yes. — Right. Okay. Yeah. Okay. It's got to break down into an acid because the hydrogen's suggesting acid. So, it's going to break down into What would the acid be? Right. So hydrochloric acid is the dangerous one. We've got no chlorine. So it's not that — carbonic acid. — No. So that's what carbon dioxide dissolves into in water. — Yeah. Yeah. — Begins with an L. That helps. — Acid that — An acid beginning with L. — Oh man, it's taking me back. Um, lactic acid. Lactic it. Lactic acid is that it just glucose from glucose to lactic acid. — And so like and again this is probably more of a chemistry question but now I've gone down this route. So if glucose is C6 H1206 what's lactic acid? — I don't know because I don't need to know. — That's fair. Okay fine. But it I'm assuming it must just have to be a rearrange I am going to guess it's got to be just a rearrangement of those things. Or maybe this is an oversimplification of the — of the reaction equation. Um because what we do actually to go on to an A level is you see how glucose in glycolysis that you said earlier is broken down into pyuvate — and then the pyuvate is reduced into lactic acid. — So you kind of look at some of those steps. Right. Okay. Cool. — So this is just the possibly simplified version. — Yeah. — But definitely the answer they were looking for. All right. — Fine. That one was a bit tougher, — but appreciate the hints. And I obviously knew the phrase lactic acid, right? Anyone who's done any form of exercise has had lactic acid buildup. Yeah. Okay. Right. Explain why the student's breathing rate remains elevated for several minutes after she finishes the sprint. Right. So, this is because um so we need to uh needs to remove pard needs to remove the lactic acid. — Yeah. Exactly. — Okay. So we remove it by um I'm going to guess is it like added to oxygen to then give nice to give CO2 and water or — that's a simplified version but yes — okay cool — so — right so it needs that oxygen — um would you say reacts with lactic acid or breaks down lactic acid — breaks down would be fine yeah — breaks down the lactic acid and they would want the products being CO CO2 and water — probably. Yeah.

— into carbon dioxide and water. Okay, great. — Um, — so the two extra ones is which organ is that going to happen in? — I was about to say is the other thing the idea that you still need like to supply oxygen for just like normal respiration or is that not really what they're getting at? — You do, but that's not what they're getting at. — It's more about this process of breaking down. — Why you need that extra Yes. Okay. Fine. Yeah. Just say elevated. Okay. Fine. So, you need to remove lactic acid. The oxygen breaks down lactic acid CO2 and water. Right. Now, this is going to occur in the muscle itself. The breaking down bit. No. So, the muscle will produce the lactic acid. — Yeah. — Yes. And then that's going to be transported in the blood. — Yeah. Um now is the oxygen going to break it down in the blood or is it going to occur the supply of oxygen is coming in through the lungs and then respiration happens over the thing in the lungs forgot what they're called the the fluttery army things — I know — excuse me — the things with the big surface area they have like the tentacles and that's why — oh so like the bronchioles branching into alvioli — alvoli I I'm so glad you said Alvi. I was about to say ioli and I was like, "No, that's like garlic sauce. " Yeah. Okay. Alvioli. Right. So the garlic sauce dip is — filled in your lungs. Millions of it in your lungs. Yeah. — Right. But it's not That feels like I'm going — No. Okay. — So think about the organ responsible for breaking down harmful substances. — So it's the liver again. — Liver. — Right. Okay. Fine. Yeah. So this And is it just me saying this occurs in the liver? — Yeah. Breaking down a liver or happens in the liver. — Okay. This occurs in the liver. So that feels like three. — The final one is going to be for a key term, — right? — Which is the term for when you need this extra oxygen to do this process. So you're basically you owe your body some oxygen. — Oxygen deficit. — They'd give it to you for that. Yeah. Oxygen debt or oxygen deficit. — Oxygen debt, right? Okay. So it's kind of like almost like starting by saying um the elevated breathing is due to oxy oxygen debt would be okay. Cool. breathing um due to oxygen debt. Yeah. No, that's a nice way of thinking about it actually because like deficit, it's a word I would use, but I feel like debt is a more everyday — term understanding term and it perfectly like is saying as you said, you owe your body oxygen, right? You're like, I'm so sorry. Like, thank you. — I got it back now. Here you go. — Yeah. With interest. — Yeast can also respire anorobically, right? the word equation for anorobic respiration in yeast and name the process. Right? So yeast produces alcohol. — Yes, — I know that. We won't ask why I know that. Um — but I need which type of alcohol. Oh, — okay. Helpful. Right. Let's think. So write the word equation restoration yeast. So therefore is it just yeast becomes two things or just yeast becomes — yeast is the organism. So that's not part of the equation, — right? Yeah, now I've read the question correctly. It does say yeast can respire anorobically. Okay. So, it's not yeast becomes that. It's glucose. — Yeah. — Glucose. Right. Now, an alcohol is an O group. — Mhm. — Right. So, there's got to be a carbon somewhere. — Yeah. — From the glucose. I'm so happy I remembered that formula because this is what's carrying me through this actually. — So, there has to be a carbon. Is it just CO2 again? — CO2 is one of the products. Yeah. Okay. — And then it's we just need the name of the alcohol, — right? Um, so yeast is going to break down the glue. I'm going to write yeast there just to remind myself that that's doing it and we're giving off energy. Glucose anorobic respiration. So yeast, — does it catalyze it? It's like a chemistry term, isn't it? I don't know. But anyway, it's involved. It's doing it's releasing the energy because it's respiration. It's anorobic so that it means there's no oxygen. — It's giving off carbon dioxide. It's producing an alcohol. But you want me to name the alcohol? — Yes. — Oh man. — And my hint is this is kind of going to link to the process. — But — is it as in like ethanol? Is that that's what Okay. Yeah. So it's like the other — that makes sense actually. I'm thinking I knew it produced alcohol because it's used in that process. But yeah, you're right. The ethanol is the correct term for alcohol specific type. Okay. — So this is anorobic respiration. But there's another term for this process. — The name of the process where glucose is going to ethanol and carbon dioxide via yeast anorobic respiration.

And this is how we make alcoholic drinks. Yeah. So, distillation, — that's how you purify. Yeah. Get the particular off. — Beginning with F. — Fermentation. — Yeah. Fermentation. — Yeah. Okay. Was definitely not buzzing around my brain until you gave me the F. So, thank you for that. — All right. And is this it? Right. It is — it. Last one. — Last one. Okay. Right. I This has gone better than I expected. It's gone very well. I'd say you're probably up there at least a grade seven, maybe a grade eight. — Okay, this is take this. — Yeah. — Right. Compare aerobic and anorobic respiration in human cells. In your answer, refer to the reactants used, the products formed, and the relative amount of energy released. Okay, do this. — Now, again, you wouldn't really get that question along with the others because you've answered part of that along the way. Um — yeah but aerobic um uses oxygen um is sort of one of the thing anorobic does not — aerobic um would you say produces more energy or is more efficient? — More energy — but you wouldn't say produce because it doesn't produce energy. — Releases — it releases more energy. Yeah. — Just Yeah. Good. Make sure I'm clear about that. Okay. So that's releasing more energy. Um what else have we got to the reactants used? Um so I've said uses oxygen products formed. So it releases more energy. Uh it forms um CO2 and water that's what it forms um and the relative amount of energy it releases more. Right? And then anorobic in comparison no oxygen um releases less energy. I know this is overkill for two marks, but let's just — be thorough just in case. — Yeah. I'm ending on a high. I'm getting sure I get the two marks. Um, and then the products are lactic acid and that's it. — GCC biology done. — I mean, I wouldn't go that far, but I'll take it if you want to give me. — Okay. Amazing. Right. Well, that was super fun. — Yeah. timely because it's actually today is paper one of GCSE biology 2026. — It's like I just went through it with you. — I sat it with them at the same time. You felt their pain. — I don't know if I felt their pain. Bless them given that I just had — they didn't have a teacher in their ear. — Yeah. Yeah. I had I had a very helpful cheat sheet. Let's be honest. And — and also only the three topics. I'm guessing there's obviously going to be a lot more. — Yeah. But would these be like three? You'd almost certainly within reason get a question on these three things. — Not for today's paper because some of those are paper two. In fact, I think most But — across the GCSE, you would expect what we do. You get respiration. — The blood glucose thing. I feel like that was just all — that was kind of like a hit and miss. That was the students like students love this came up one year and it's hard like Yeah. Yeah. — The inheritance that's pretty common. — Yeah. Okay. Well, I'm glad the math is in there. And obviously that was my favorite question. No, I did enjoy it all. Like it felt um it was a nice reminder of some of the chemistry equation stuff here. — It was quite chemistry based, wasn't it? Yeah. — Yeah. Um and the kind of pathways and I'm glad I remembered that the liver does a lot of the breaking down and clearing out of waste. You know, there's still things — good to know that all of the math hasn't pushed all the biology out of my brain because it's been a many years of just maths and nothing else. — So, um but no, that was really fun. So, thank you so much for um coming to Oxford, hanging out in the old library. — Yeah, thank you. — And um thank you again for excellent questions and being a fabulous not only a fabulous cheat sheet, but also a fabulous teacher. I feel like you really help me actually to understand and remember a lot of those things. — Yeah. Not to give you the answer. — No, exactly. Right. I can tell you're a teacher and a very good one at that. So, if you would like to go and learn some biology, right, you know where to go. Miss Est biology. Obviously, we'll link everything in the description box. Go check it out. All kinds of GCSE biology, Alevel biology, I'm sure many other cool stuff, right? Related to biology. — Um, and we are going to do a part two. I'm now very nervous — in in these usual collaborations for those of you who are here that have seen me do these before. So I have just put myself through biology. — You're now about to put me through maths which I haven't done maths for 22 years. — Okay. — Apart from maths and biology. So there's a small bit I'm skilled at. — The rest though I am I'm really worried. — So go watch that. And if you have enjoyed this video, then please remember

to subscribe to my channel so you can also get lots of maths teaching. I'll see you soon.