Hi. Hello. Hello. Can't hear you. No, I can't hear, let me just. 那时候的歌名。Hello, I can hear that or I can see that working anyway settings. Does it have a sound? Hello. Hello. Yeah, I can hear that. 马随便你看。Hello. Yeah I can hear you. Can you hear me? Yeah, I can't hear. Okay, okay, perfect. Right. Okay, so last time we had a lesson last week we were looking at reproduction, talking about mitosis and meiosis of cells. And have you done a bit more of that in class this week? Yeah, athrosis. Yeah, Yeah. So you've done my tosis and meiosis. Nearly done. And last two lesson or finish. Yeah. Yeah, okay okay. Have you done anything on inheritance? Did you do Yeah, like does this look familiar to you? If I was to do something like this, does this look familiar? Or not? Yeah, Yeah Yeah Yeah, you've done it. Yeah okay. How have you found it one day? Easy, hard to together. See that again, showing easy. I say as a plus, again, just play together the big b and the small b. So the pnet squares you're okay with. So what I wanted to do then was before we talk about maybe variation and evolution, but I just want to test your terminology for this topic because there are for this topic in particular, there are quite a few words that are important that we know exactly what they mean. So I'll do that in a minute. First of all, I just want to have a quick discussion about dna. And sorry, actually I'm just going na bring my laptop down here, use my iPad. So dna and the genome. Okay, so I just want to have a quick talk about this. Now, human dna looks like this, or at least we draw it like this. Okay, so here's one strand. You'll recognize this structure because the way I'm drawing it, it's a very common way to draw dna, also very common colors as well, right? So we do tend to use red and blue, but I'm not too sure why, it just makes it easy to distinguish between the two. So have a look at this diagram. This is a molecule of dna. Okay? So this is a molecule of dna. Now I'm going to put here, this is a molecule of dna for your specification. I mean, I know you said you're pretty sure we're doing combined foundation. We don't need to know the specific structure of dna as in the nucleotides, but we do need to be able to comment on what it looks like. So tell me, what are some features are dna? So that's a question for you. So have a look at the diagram I've drawn. What are some features of dna? What does it look like? What does it contain? What are some features of dna? Yeah, some properties and characteristics. Oh. Patches. Ich of. Like you can. Write something down if you want to. By the way, if you find it easier then trying to say it features, I mean, have a look at the dna molecule that I've drawn. What are some observations we can make about it? You. How many strands is it made up of? So I'm going to add a discussion question in here. How many strands is it made of? Yes, well done too. Fantastic. So it has two strands. You've got the blue strand and the red strand. So that's strand one. Yeah. So we call it, what do we call that? You know there's two strands. What do we call it? The structure of dna, like the shape of it. At and and cg. Okay, well done. Yeah. So the bases are atc and g. Excellent. Well done. So there are four bases. Atc J, excellent. Well done. What do we call the shape of dna? What do we say? What do we how how do we describe? I'll type it. How do we describe the shape of dna molecules? Shape of na? How do we describe the shape of dna? Sorry, I'm just going to shut my door until the dryer is making a lot of noise. Yeah the shape of the dna. What do we say about it? There's a phrase, yes, well done. Excellent. So it's the double helistructure, double helix. Excellent. Where do we find dna? Yeah where is dna? Hwhy is it? I'll type this question out as well. I don't know. Cell is dna found. Have a think about it because I think you'll know this. Which part of the cell holds the dna? In the cell sorry, minc is a dna farwhere. In the cell is dna found Yeah. I'm talking about animal ble cells, human cells. The. Hold, type it if you want to remember. Cleyes, well cleexactly excellent. So in the nucleus, so dna is found in the nucleus of every single cell. There is lots of it because it codes for all of our characteristics. It codes for proteins. So I'm just gonna to highlight a bit of this dna. Okay, so imagine this is a whole dna strand. What would we call a small section of the dna? So if I just cut off a small section, what would I name this if it's just a small section of dna? I'm not understand. I'll write it here. So this is a I'll type it so that there's a missing word, a short section of dna that codes for a particular characteristic. Is called a. A short section of dna that codes for a particular characteristic is called a what? Center rain. So. Means I'll drop me to give you the first letter. Oh, I know the answer, but I forgot what this means for this word. So you know the answer question, you don't know the word. Oh, particular, like a specific characteristic, ascertain, understand, says. Good. Yes, well done. Excellent. So it's a gene so particular or specific. Sorry, I used a bit of a peculiar word, but it is a gene. Excellent. Okay, next one again, missing word. A gene codes for a specific sequence of now this is two words. That build a protein. So there's two missing words, a gene code for a specific sequence of something, something that build a protein. It was again here. A moor something. Yes. So like I forgot. I forgot amino acid. Amino something, well, amino acid, acid, acid. Okay, there you go. Well done. Amino acid. So amino acids are the monomers and the protein is the polymer. So what would happen is quite literally, this this would be the process of translating dna and then a protein being built. So here's your dna. Each gene, I'm just going to highlight one gene, but I'm going to make it quite a long one. So let's say from here to here. So this is just one gene. So that's the gene. And that codes for a specific sequence of amino acids. So they might be different types of amino acids. So let's say we've got one, two. Three, four, just kind to do a couple of the same five. Ten and then eight. Okay? So these are all different amino acids. All of these circles represent amino acids. So these are all amino acids. And then what happens to them is they are all added together. They all are bonded together to form a final protein. And proteins are what give us our characteristics. So proteins can be enzymes, they can be hormones, they can be pigments, they can be structural proteins. There are so many different roles that proteins have because that is the basis of life. Okay, so then that one would be the protein. So dna is so important because it holds the information that's needed to build proteins, and proteins are what we are made of entirely. Now I've got a new word for you as well. I'm just going to again, I'm going to use the missing blank space. So the complete set of genes that are present within any cell. Is called the something. Okay. So the complete set of genes, not just one, but all of the genes in a cell, what do we refer to it as? It's also a word beginning with g. Okay, the first letter of this word is also g. Wait. 株友汗知。Three. 嗯。Oh. God, me nome this one. So g nome. So what that means is it's Yeah, have you not have you heard that word before? Do you recognize it? Not. Yeah. Seven, a little different chimps. Did you say I'm in the ten. The genome similar to chimt of humans. What did you then? Nothing, nothing. No going. Because I think you might be right. I'm just checking which animal you said. I mean, geno is a cook and this. Oh you mean the similar words? Yeah, Yeah, Yeah, definitely. I thought you said similar to chimp which means like I thought you were saying the genome was similar to that of a genwhich is so that's why I thought that's what you said. So the human genome okay, so let me write something here. The human genome has been sequenced. Okay? So what that means is we know the all of the genes, we know all of the genes that humans have and where those genes are. Okay? Now what I mean by that is we have as humans 46 chromosomes. Yeah we have 23 pairs and all of those chromosomes have genes and those genes are found in very specific places. So let me give you an example of a chromosome and we'll say where a couple of the genes are. Now I'm making these up, okay? I don't actually know where every gene is in the genome, but this is a chromosome. Okay? So this is chromosome. I don't know. Let's let's just say it's chromosome one. Okay? So this is the chromosome one pair. So this is the chromosome one pair. Now I've got a question. Why do we have two of each chromosome? Why do we have two of each chromosome? Yeah, think about really think about this. Think about inheritance. Why do we have two of everything? Because what else do we have? Two of all humans have two something. I'm writing out a sentence here which will help you. We get one chromosome from our something and the other from our something else. Oh. It's mother and father. Well done. Yes, perfect. So it's mother and I know, you know that's why I didn't say anything. Mother and father. So we get one chromosome from our mother and the other from our father. So we have two copies of each chromosome times 23. So we have 46 in total on each chromosome. The genes will be in a specific place. Okay. So what I mean by that is on this chromosome, the first gene might be the gene for, let's say, eye color. Okay, now I am making this up. So this is the gene for eye color. And the second one might be the gene for blood group. Okay? So I call a gene and then blood group gene. In fact, you know what? I'm just going to type it so I can make it neater on both sides. So this might be the eye color gene here. So that controls your eye color and this one is your blood group gene. So that controls what blood group you are. And that means that this this one came from the father, okay? This one came from the mother, but the genes are in the same place because that's the nature of being a human. So me and you, we are both humans, okay? So your genes are in the exact same place as my genes. You have all the same genes as I do and I have all the same genes as you. What's different about me and you is we have different allals, okay? So we have all the same genes because we're both humans, but our alleles are different and that's what causes variation. Okay? So I'm gonna to actually ask you the question before I fill in those eye color our bits. What is an allele? You might call it an allele. I've heard many ways of pronouncing it, but an allele, do you recognize that term so far? Because I you've said you did the big beand, the little b, they're alleles. But what is an allele? So this question here, what is an allele? You Yeah, alu. Well, is argue, do you recognize the word? No, no. Okay, that's absolutely fine. So I will tell you what an Aliot is then. Now this is probably where you must have got up to. So an Aliel is a version of A G. So an alol is a version of a gene. I'm just going sorry, once I nearly went off this person. An allol is a version of a gene. So let me give you an example gene. So the name of the gene is the eye color gene. So that's the gene. The alloles are what color eyes can you possibly have? What different color eyes can humans have? What colors have you got? In you say what color eyes have you got? Black. Black. Right? So you can have black eyes. Brown. I've got Green. So I'm adding Green in there. Blue. Hagel, I think they're the main ones. Okay. So the Genean is the eye color. So that's the actual characteristic. But the alleles are the versions of that gene. So basically the options that you can have of that gene. So me and you, we both have the eye color gene, okay? But yours, you have black aleles and I have Green alleles, okay? So we have the same gene, but the version that we have is different and that's what causes variation. Okay? 1s, I don't want to copy this whole thing. I just want to take this down here again. So just to go back over this, the genes are the characteristics, but you can have different letters. Okay? So that might have given capital b, which is for Brown, and mum might have given lowercase b, which is blue. Okay? So this is the alle for Brown eyes and this is the aliele for blue eyes. Okay? So that's what alleles are. They are different versions of a gene. Let me give you another example of gene is blood group. Do you know what blood group you are? You know what type of blood you have? Like letter. Like you can either be A B, A, B or o. You know have you been to the doctor before? No, you don't know. Okay, that's fine. So you can have A B, A, B or o. Okay. So they're your alleles. Actually, they're your genotypes, but phenotypes, but anyway, they're your alleles. Okay? So they are the different types of that gene that you can have. So the blood group gene is something that you have and I have you have it in your dna. I have it in my dna because we're both humans, but you might have type a blood, whereas I've got type b blood. Okay? So that's what that's what causes variation. So the gene is the actual characteristic. The alleloles are the different versions of that characteristic that an organism can inherit. Now I want to go back to this example here. So I've used Brown capital b and blue lowercase b. So I'm going to just type this in. Aleles can either be dominant or recessive. Okay, so dominant or recessive, do you recognize those terms about alleles? No, no, dominant. Okay. So do you know when I said at the start about the Ponnet square about this, had you done it? No. Like you know when I said, have you done have you done this? So you have done this, right? Yeah. Okay. So tell me, what does this mean? Like how would I complete this table and what does it mean? What is me? Yeah, so when you, when you did these tables in glass, how do I fill it in? I don't know. Okay, so we'll do this together in a second because I'm just when you said you did it, that's like aleles and dominant and recessive. So maybe you've just seen one of these but not gone through the specific details of the genotype. So an alio can either be dominant or recessive. Now the word dominant means a dominant allele is an allele that only needs to appear once to affect the characteristic. I won't talk about genotype and phenotype just yet, but to affect the characteristic, a recessive allele is an aliele that must appear twice. To affect the characteristic. So you have two copies of every chromosome, remember, which means that you have two copies of every gene. Okay? So a human has two copies of every gene, which means that they have two alleles. So every human has two copies of every gene, meaning that they have to alleles for every gene. However. When they reproduce, only one allele is passed on. Why? Okay, so read this sentence that I've put here and I'm going to move everything else off the screen for now because I just want you to focus on that sentence. Every human has two copies of every gene, meaning that they have two alleles for every gene. However, when they reproduce, and when I say they, I say I mean, when humans reproduce, only one allele is passed on. Why? Ignore my drawing for now. You keep thinking only one Aliel is passed on. Why? Only knew why are this? I don't know, really have a think about this one, you don't have to answer it quickly. Why do you only get one thing from each parent? Age. Okay, wait, I have something maybe. 终于忘了再。I remember what, but I forgot how to say. So you know we have a gone but there's I'm I'm something yes, well done. It is it's the selkeep at that one. Try and write it then try and write it because I think you've got it. Yes, well done meiosis. Excellent. There you go. I yes, that's the answer. Meiosis. So it's because reproduction or the the making of reproduction tive cells means that only half of the dna gets put into a reproductive cell. Okay, miosis, well done. Excellent. Okay. So meiosis, meaning that when a new life is formed, it's made of half egg, half sperm cell, and that produces a new life. Okay, well done. Great work. So I'm gonna to show you a diagram here. I've drawn two little stick figures, a mother and a father. The mother is the pink one and the father is the blue one. A slightly stereotypical, I know, but it helps to show the difference between the two. So mother is on the left in pink and father is on the right in blue. Okay, now I've written in White there. This diagram shows the two alleles that each parent has for the eye color gene. The mother has capital b, sorry, lowcase b, lowercase b, and the father has capital b, lowercase b. Now here are what those alleles code for, capital b and lowercase b. Okay, so capital b and lowercase b. So I'm just going to write here. Capital b is a dominant allele. And podes for Brown eyes, that's why I've done it. Brown, okay. A person only needs to have. One capital b allele and they will have Brown eyes. Okay. So that's the capital bit. Lower case b is in blue. So as you can probably guess, it does code for blue eyes. So the lowercase b is a recessive aliele. And codes for blue eyes. A person must have to be allels to have blue eyes. Okay, so there our allels. Okay, so have a look at the mother. First of all, let's have a look at the mother. She has got capital. Sorry, lowercase b. Lowercase b. So what color eyes does the mother have? What color eyes does mother have? Have a look at her here in the pink at the bottom there. What color eyes does she have? Based on all of the information that I yes, why does she have blue? Why? How does she have blue? Why doesn't you are right, why doesn't she have Brown eyes? Because only one is Brown. I saw. If Hey any malso only have the blue eyes, I have other one. Okay, so she has not got Brown eye alot apple, okay, let's have a look at the Farthen. Let's copy him in here. What color eyes does the father have? Your father have. Yes, Yeah. Why? Because he has Brown and blue, so why does he have Brown eyes? I don't know. Well, why did you guess Brown? No idea, just guys. Okay. Okay. The reason why he has Brown eyes is because he has one of the dominant alleles, okay? So he has a dominant allele. And even if he only has one of them, the capital is stronger, okay? So the letter that is the capital letter, so the big b, that is the stronger allele. So it will win. If it fights with blue, it will win. Okay? That's the idea. If it is a capital letter, the capital letter will always win even if there is a lowercase there as well. So with the father, he had capital b, but he also had a lowercase b, but because the capital b was there, that is stronger. Okay? So that was the reason why he has Brown eyes. The way that we show it in inheritance is capital letters show dominant alleles. So I'm just going to put here, use capital letters to show the dominant allele with the recessive allele. We use lower case letters, okay, always. So capitals for dominant, lowercase for recessive. Now that's our parents. Okay? So what we're going to do is we're going to do something called a genetic inheritance prediction. So in this topic, we use pnet squares to predict the characteristics of offspring based on the characteristics of their parents. We do this for one gene at a time, for one gene at a time. For example, eye color, which is of course what we're looking at right now. So the way that you draw upon its square, is this, okay? You do like a little table with two lines going vertically, okay, like this and then two lines going horizontally. So this is your pnet square, okay? That there is a pnet square. Then what you do is you fill in the parent letters, okay? So I'm going to put mother's letters, and then down this side, I'm going to put the father's letters. And I mean, like the bees that they have, so the mother's letters are going to go on the top and the father's letters are going to go on the side. And when I say at the top, mothers is going to go here and here, and fathers is going to go here and here. So let's remind ourselves, okay, let's look at the mother. I said that the mother has lowercase b and lowercase b. Okay, so that's her two letters. There are no other letters. There's only two for each person. And the father's was capital b, lowercase b. Okay. So do you see what I've done there? How I filled in the pnet square? Yeah. Okay. Now we use this to predict the characteristics of the offspring. So I'm going to put numbers in these four boxes, one, two, 34. So basically, we're trying to identify the chance of certain characteristics in the child. Now what we do is to find out the characteristics of each child. You look at how the letters cross. So for number one, we would see what two letters cross into this box. Do you see what I mean by that? You see what I've done there? Yeah, Yeah. Okay. So what would the two letters in number one be? Well done. Okay. What about in number two then? Number three and number four. Okay, perfect. Well done. So we have two of the offspring that have capital b, lowercase b and two of the offspring that have lowercase b lowercase b. So let's go back and I'm just gonna to copy this bit in here. I'm just going to copy this and bring it back down so we can decide what color eyes our children have. Okay, so this is the information. Okay, so let's just look at the square. So what color eyes will number one have. What does that mean? So if number one has capital b and lowercase b, what color eyes will they have, Brown or blue? Yeah, well done. What about number two? Yep, same Brown. Okay, what about number three? Blue? Yes, well done. And then number four, blue. Excellent. So this pnet square shows us, so this square shows us that out of four possible children, so for possible children, two of them will have Brown eyes and two of them will have blue eyes, or they are predicted to have so there is a 50% chance of Brown eyes if this couple had a child, 50% chance of Brown eyes, 50% chance of blue eyes. Okay, so 50% chunk of Brown, 50% chance of blue. Well done. Right? I'm just going to do one more cross, but I'm going to change the parents genotypes now and I'll leave the information there. And I want you to do the same thing. I want you to fill in for me what the outcome would be. So I'm going to do dads, Scott or mu's got t capital b, capital b, and then the other one's got lowercase speed, lowercase b. So can you do that for me again? And just write in each box what the genotype is. So what the two letters are that this offspring would have, and then what color eyes they would each have. Oh. There's no different. Do they have different? Just try it. See what you get for each box. Me big pmovie. Well, let me try. They're same. They're all the same. They're all the same. So what color eyes do they all have? Color is always a blond. Blonde, you've written yellow, so you've put blond. What color eyes do they have though, with the capital b? How would it be? Okay. Is would you say blonde? Well, what color is capital b? Okay. Have a look at the information above because I've put the capital in the lowercase b with a bit of information next to it. So have a read at the Brown and the blue one. What does capital b code for? What color? Yellow. You've drawn it in yellow, but I didn't draw it in yellow. What polar did I draw it in? Brown. Exactly. So the offspring will all have capital bealowercase b as the dinner type, and therefore. They will all have Brown eyes, okay? So they will all have Brown eyes. So that is what we call a genetic cross or a pnet square. So the two letters that you have for any gene, let's say that you have capital b and lowercase b, that is your genotype. So capital b, capital b, capital b, lowercase b, lowercase b, lowercase b, all of these are what we call a genotype, okay? And that means the two letters that you have on your chromosome or on your genome. So that is a genotype. The letters Brown or blue. So the characteristics that you see, Brown or blue, they are your phenotype. Okay? So genotype. Is the letters that you have, and the phenotype is the characteristic. Now have you seen those words before yet in class? You recognize those Gena type. No, okay, that's fine. So the genotype of the individual is the two alleles that they have shown as two letters. And the phenotype is the characteristic that we see. For example, blue eyes, Brown eyes. Okay? So that's the characteristic that we see. So the genotype of an individual is the two alleles that they have, and that's the two letters that we write. So capital b, lowercase b or lowercase b, lowercase b or capital b, capital b and the phenotype is the actual characteristic that we then see as a result. Okay. Before we go, I just want to ask you something. In humans. Cells can. Be either male or female. So there are two options in humans, okay? That is determined by two letters. One of them is X, X, and the other one is X, Y. Do you know which way around they are? Which one of those is a female and which one of those is a male? So these are the two genotypes, which are the two letters that you have. Which one is female? Which one is male, do you know? No, no. Okay, that's fine. We can continue this next time. But two x's is a female. Okay? So two x's is female, so I'll put that in pink again. I know it's stereotypical and xy is male, okay? So in all of my cells, I have the xx on my chromosomes because I'm female. On your cells you will have xy because you're a male human, right? So that is what determines whether a human is male or female. Those two letters. So the genotype is the letters and the phenotypes is what actually happens as a result of those letters. It's what we actually see as a result of those letters. Okay, right. I'm going to stop there. I'm not going to tell you anything else new today. So you haven't done pnet squares yet in class, but you were able to fill them in quite well, which is good. You've done really, really well today, a lot of the words you were able to say, and you filled in the gaps really well. What I think we might do next week is Carry on with some inheritance graphs, some pnet squares, including male and female inheritance. Okay? So if you do Punit squares in class this week, let me know and I can make them a bit more difficult that way. But the key words for today, okay, are alel, which is a variation of a gene, a version of a gene, dominant, recessive genotype and phenotype. Okay? So if you can try and have a look through those words, even if you do them in class this week, that would be great. And then next week we'll continue with it. Okay. Yeah, Yeah. So well done today. You're done really well. Do you feel like it's made sense? Yeah, Yeah. Okay, good. We'll continue next week and make sure, but I'm happy with most of it. Obviously the Punit squares you're able to fill in, which is good. We'll need to revise the terminology, but apart from that, I think is making good progress through this topic all so I will let you go a little bit early because I don't want na introduce something new now. I will see you next Sunday. Okay, okay, okay, see you then. Bye bye. Yeah.