GCSE Biology - DNA Part 2 - Alleles / Dominant / Heterozygous / Phenotypes and more! #64

[@Cognitoedu]

If you’d like to practise the material covered in this video, check out our platform at www.cognitoedu.org - it's totally free, and has been built to make learning and revision as easy as possible. The main features are: - Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown. - Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on. - Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like. - A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts. - A comprehensive bank of past exam papers, organised both by year, and also by topic. Amadeus & Tom

[@fearnbishop9563]

I have been reading open university tutorials on this for ages and felt so confused and you got it in 4 minutes. We are so flipping lucky to have you about!

[@thoughtsbright7928]

He explains a lesson in 4 min while my teacher takes the whole lesson and best of all is it free and I study alone so no "distraction".

[@Niels596]

The purple and green mice became really dominant in my understanding.

[@nehamjohn6099]

N I C C E

[@prim7267]

N I C C C E

[@anuragthakur4341]

N I C C C C E

[@neolight2922]

@@anuragthakur4341 N I C C C C C E

[@ellieevans5251]

N I C C C C C C E

[@catherinerobinson798]

Thank you so much this video was a life saver! Textbooks rly make no sense sometimes so i was clueless before watching this

[@Great_sri_lankan]

The way he finished was like he was waiting to finish with this if we understood or not

[@junsaung7958]

Fr😭🤣

[@IzzyCollins-q8m]

Literally the best teacher, thank you!!

[@지지지-v1i]

Omg.. this is the most informative video ever

[@han.jisung-s_cheesecake]

Thank you, this really helped me understand what's going on in my classes 🤩

[@javeriarafiq2449]

Thanks so much! This video really helped me understand what my teacher was talking about in lesson, haha I was so confused this cleared it all up and more! You got yourself another subscriber. :)

[@spiceyblueroyalhoney1225]

wait so why do mix raced children not have just one of the parent's skin colour but have a mix of it?

[@WitheredGurl]

I like how he didn’t answer you yet lol xD

[@spiceyblueroyalhoney1225]

@@WitheredGurl maybe he won't answer me because it's been a year.

[@weallyplstop3517]

@@spiceyblueroyalhoney1225 bruh mode

[@tawfiquemungi4691]

Skin tone is determined by percentage of melanin in the skin cells so i think that it just varies it doesnt work like dominant recessive but usually leans towards one of the two

[@amritamallick4895]

That's because human skin colour (phenotype) is controlled by multiple genes, and not just a single dominant allele of a gene. Skin colour in higher animals like humans, is a Polygenic trait.

[@TheAsKUPSC]

Thank you so much, Cleared a lot of confusion!

[@enaams7937]

Best one so far!

[@arvindshah9183]

i always know that this guy has my back

[@mahnoorkhalid6213]

This was very informative 👍🏼

[@louisperry2129]

1:04 - bookmark for me

[@abdullahnooreldinalkhawari704]

2:44 Alice and the wonder mice!

[@bassamhadi7930]

What’s the difference between genome and genotype?

[@varunibaiju9926]

the genome is the organism's ensemble of genes. The genotype is the individual organism's unique set of all the genes.

[@lukeyboi9339]

Thank you I have a test tomorrow

[@Cognitoedu]

Best of luck!

[@mattyABC1]

did you do well

[@yaut1172]

@@mattyABC1 3 years late mate

[@thelittlecommentator6576]

You didn’t talk about the Punnett Square

[@mattyABC1]

different vid

[@lakrasia]

Cripes, that was good. I hope it helps me with my Open University foundation course - I'm struggling with the biology.

[@t4aha.s]

Cripes 💀

[@CT-sn3hx]

at 2:18 how do you know which is dominamt mouse and which is recessive? would we be told in the question?

[@GraceY-ig2cr]

The dominant allele is always the big letter, the one in capitals. For example CC , or C c. In this re both dominant as the dominant is always expressed

[@CT-sn3hx]

@@GraceY-ig2cr first, thanks for answering my question, also does that mean the dominant alleles will be give to us like in the question "Cc"

[@GraceY-ig2cr]

@@CT-sn3hx the capital letter is always dominant( always expressed)

[@CT-sn3hx]

@@GraceY-ig2cr ohh I see now, thank very much!!

[@gunnu9855]

Hi sir , this video is very helpful . I understood most of it except I had a query at 2:38 , when u said the mouse has to have both alleles for green fur being homozygous recessive to have the green fur characteristic , although what would happen if the mouse had recessive allele for both colours so if it had a recessive allele for purple fur and a recessive allele for green fur , what colour would the fur be then ? Or if the mouse had a dominant alleles for both colours?

[@javadshirinov3750]

There would never be two dominant so in this case the purple will always be the dominant and the green recessive. So in another example the eye colour, there is Brown which is dominant so we use - B, and a blue iris which is - b. So there always is one recessive and one dominant feature

[@sarahbreant2811]

Well they would just be codominant which basically means that the offspring’s fur will be a mix of purple and green(whatever colour that makes?!), because there isn’t a dominant allele because they both are in this case. I hope that cleared it up :)

[@Skinny_dweeb]

Sarah is hard waffling, ignore her

[@faizbinsaleem340]

2:55, in the diagram, you've written homozygous purple. Question is that whether that is homozygous purple or a homozygous dominant? Colored purple

[@zelkaa3839]

the homozygous mouse contains 2 recessives alleles so it will be green anyways because theres no dominace, while the heterozygous mouse has 1 dominant allele which is purple causing it to be purple,

[@alyssastar4326]

GOD BLESS YOUR SOUL thank you!

[@tudord3067]

veri nais helpd mi alot uit mai test

[@abdullahjaved8963]

Didn't you say two alleles of each gene (2 from mother 2 from father), so shoudn't there be 4 different genes. Which of them are dominant and which of them are recessive?

[@arnav.k9650]

I hate people who dislike

[@melikazamani4077]

im getting good grades cuz of u

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[@atrz_]

Are his videos like, mark scheme specific?

[@spartn_7]

idk

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its a god damn gamechanger !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@TenzinChozom-q2n]

Sir, your just great.

[@maroniaduca3503]

Really helpful, THANK YOU!

[@qt_s]

i... dont understand....

[@qt_s]

pls help

[@hamzie1010]

1) Alleles are different versions of the same gene. Alleles codes for a particular type of protein, however, it copies the protein structure of a particular gene. Different type of proteins with the same structures involve a different type of genes to code those proteins. We call those different genes alleles. In other words, alleles are different versions of the same gene. And because we have 2 copies of each gene (one from our mother and one from our father), we have 2 types of alleles. Remember how I said that these alleles code proteins? Well, if those 2 alleles are different, we will say that we are heterozygous. If they are the same, we will say we are homozygous. However, with heterozygous people with alleles which are different, one allele will be DOMINANT and the other will be RECESSIVE meaning the dominant one will always be expressed (carried out). In homozygous, both alleles will be expressed as both are the same. Genotypes are the sum of all alleles (all the collection of alleles), but phenotype if the same characteristics that are displayed, even if they have different genotypes. I know, it's tough learning this stuff, but delve deep and research. You'll get there :)

[@qt_s]

@@hamzie1010 omg thank you so muchhh! You have no idea how long I've been trying to learn this stuff and this really helped! Thanks :)

[@hprivate9114]

@@hamzie1010 do you know what exam board these videos are based on or if their just all boards

[@hamzie1010]

@@hprivate9114 My exam board is AQA and it contains all the things in the video. If you're doing AQA biology, you will probably need to learn this. On some of the videos, the description states whether it's a specific exam board or not. I hope that helps.

[@Rachel-y1b]

Thank you soooo much

[@FelixSikindo123]

Very good

[@miadancona3679]

genetics is the easiest topic but conf sometimes

[@rose-pp8xj]

Thanks helped so much but I'm still confused How would u know which is dominant and which is recessive

[@HumbleMonsterUK]

It’s like eye colour brown is dominant my dad had blue eyes mum has brown mine turned out brown/hazel

[@Levi-ev3xg]

yk chippy chips?

[@migztreg582]

Thank You

[@issamhassanghosn2326]

you're the best, thank you so much !!!!!

[@Bella-zq4td]

thank u that was helpful!!

[@slivvr8300]

Lmao hi mr madden's class my wallpaper is nft collection (dont screenshot+ratio+cope)

[@leong7958]

THANKS BRO

[@ibbayallay]

i dont get it i'm only in year 8 this seems like GCSE

[@FarmYardGaming]

I'm in Year 11, so... yup, seems so.

[@ibbayallay]

@@FarmYardGaming lol

[@srutea]

this is a gcse biology video tho-

[@Itz_glori]

Well you'll be doing your GCSEs soon so it might be helpful now

[@Dingos.podcasts]

I'm in grade 7 bro I'm cooked

[@jakiasultana9774]

You are the bestttt!!!😭

[@livinghope8039]

Simple and great explanation! I have just SUBSCRIBED AND LIKED your VIDEOS! Thank you!

[@Cognitoedu]

THANKYOU very much!! 😊

[@gamer_ksa9517]

Thanks

[@jamka5]

good vid

[@jamka5]

thanks

[@moizahahsan5306]

Ok now the last part I did not understand

[@richardsmith9399]

I have a question? I understand how it works with woman+man, but how does it work for man+man or woman+woman? I am so confused

[@melikazamani4077]

Ily

[@hjqp]

no

[@pianostream1565]

0:20

[@zahsoxfordacademy9083]

Nicce

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I love you

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mwah

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Loll

[@darksoar3633]

i disliked for no reason.... good vid though lmao

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Please don’t teach fast

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[@lilianeluvsmusic]

literally saved me tqsm 🕺

[@Anasjamal-b5n]

Please don’t teach fast