Hi check the description in the video. On the final question i made a mistake. I have put the solution up for it. I will be releasing lots more videos over the coming weeks and may do some revision live sessions before the exams
The 0.058 represents the proportion with black fur. Eg 2/34. Black fur is a phenotype caused by a genotype. A genotype has 2 alleles we are told that these are cBcB that means that 0.058 represents either q2 or p2 our choice. If the question wanted to know the proportion of the phenotype or genotype we would not need to square root it. However in this example we need to find q so we must squareroot q2. It all depends on what the question asks for. If it wants the frequency of a single allele like p or q you normally workout p2 then square root to find p. Once you have either p or q you know both as they equal 1. Then you can also find the proportion of heterozygotes by doing 2 x pq. Basically it all depends on what the question asks
I got the same answer as you the first time. However when i checked the AQA MS the answer was 44% It appears they have done 0.33*0.67*2. But this wouldn't be correct. Do you agree? The MS must be wrong?
ooops my mistake thanks for pointing out so where I go wrong here is that I assume q^2 is 0.33 however the frequency in the table is just for the single allele q is 0.33 so really I should have done p+q=1 so as q=0.33 p=0.67 so the heterozygous are represented by 2pq so 2 x 0.67 x 0.33 =o.44 so the percentage is 44%. If you look at the table that shows LONDON allele frequency is 0.33 the mistake was thinking that represented q^2. Going to use the excuse that I had a cold when doing this vid so missed that one arrrgh. Checked the others on the vid are correct but will need to put a correction in the description for this.
Hi these are A level exam questions from past papers from the last 10 years I believe these are aqa but might have edexcel or ocr in there too as I use all of the different exam boards
so glad i've found this account! you're really great and I've been looking for something like this for agesss
@@nefertiiti.777 Let me know of theres any topics you would like a video on and ill do a walk through for some questions
Really helpful video!! Thanks !!
So happy I found your account! I’m about to take A-level bio and chem exams so this is really helpful
Hi check the description in the video. On the final question i made a mistake. I have put the solution up for it. I will be releasing lots more videos over the coming weeks and may do some revision live sessions before the exams
Very clear explanations, thank you !!
your videos are very helpful , thank you!
Could you do more biology content videos where you do a walkthrough with questions pls
No problems which exam board? A level Biology exam papers?
@@letsgettothemarksi think you should do AQA
@@letsgettothemarks can you do CCEA please?
7:46 why do you have to sometimes square the 0.0588 and sometimes the mark scheme tells you not to. I hope someone can help me please.
The 0.058 represents the proportion with black fur. Eg 2/34. Black fur is a phenotype caused by a genotype. A genotype has 2 alleles we are told that these are cBcB that means that 0.058 represents either q2 or p2 our choice. If the question wanted to know the proportion of the phenotype or genotype we would not need to square root it. However in this example we need to find q so we must squareroot q2. It all depends on what the question asks for. If it wants the frequency of a single allele like p or q you normally workout p2 then square root to find p. Once you have either p or q you know both as they equal 1. Then you can also find the proportion of heterozygotes by doing 2 x pq. Basically it all depends on what the question asks
@@letsgettothemarks so basically if it asks for the heterozygous you square root it????
@@Lavin. It depends what the question asks and what they give you in the stem.
I got the same answer as you the first time. However when i checked the AQA MS the answer was 44% It appears they have done 0.33*0.67*2. But this wouldn't be correct. Do you agree? The MS must be wrong?
ooops my mistake thanks for pointing out
so where I go wrong here is that I assume q^2 is 0.33 however the frequency in the table is just for the single allele q is 0.33 so really I should have done p+q=1 so as q=0.33 p=0.67 so the heterozygous are represented by 2pq so 2 x 0.67 x 0.33 =o.44 so the percentage is 44%. If you look at the table that shows LONDON allele frequency is 0.33 the mistake was thinking that represented q^2. Going to use the excuse that I had a cold when doing this vid so missed that one arrrgh. Checked the others on the vid are correct but will need to put a correction in the description for this.
where are these Qs from?
Hi these are A level exam questions from past papers from the last 10 years I believe these are aqa but might have edexcel or ocr in there too as I use all of the different exam boards
@@letsgettothemarks thanks, i just came across you and this video is so helpful pls do more content ☺️🤯