CHROMOSOME mutations - A level biology. Nondisjunction in meiosis. Aneuploidy & polyploidy

Mutations in the number of chromosomes can arise spontaneously by chromosome non-disjunction during meiosis. See how non-disjunction in meiosis I and meiosis II can result in aneuploidy and polyploidy.
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Пікірлер: 60

  • @chineke3456
    @chineke34564 ай бұрын

    i hate meiosis omg

  • @torriches
    @torriches3 жыл бұрын

    This has just saved my life not to be dramatic or anything but I’ve not understood this for over a year and now I do

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Hi Victoria, that's great! So glad you are more confident. Pleased it helped 😀

  • @jamesklieve4620
    @jamesklieve46203 жыл бұрын

    Just finished the AS playlist with a bunch exam questions after each unit to consolidate, all going more or less perfectly c: Thank you!

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Amazing 👏! Great consolidation and revision strategy. Hope they videos help with your studies 😊

  • @rip_6998

    @rip_6998

    Ай бұрын

    what grade did u get x

  • @sarahm5376
    @sarahm53763 ай бұрын

    Substation ans deletion ?

  • @i_am_gods_child
    @i_am_gods_child3 жыл бұрын

    this helped so much!! thankyou for explaining everything so well

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Hello 👋🏻 So glad it's helped you to understand 😊

  • @MrMidoo2010
    @MrMidoo20104 жыл бұрын

    Always fabulous Miss Estruch.

  • @MissEstruchBiology

    @MissEstruchBiology

    4 жыл бұрын

    That's very kind! I hope the video helped

  • @nitinagunawardhana
    @nitinagunawardhana2 жыл бұрын

    Thank you very much. This did really help me to understand clearly what aneuploidy and polyploidy means.

  • @MissEstruchBiology

    @MissEstruchBiology

    2 жыл бұрын

    So glad it helped you!!!

  • @maris4416
    @maris4416 Жыл бұрын

    My oral biology A level exam is tomorrow and this was an absolute life saver, thanks!

  • @omarmohammd5276

    @omarmohammd5276

    2 ай бұрын

    oral?

  • @poppydowse7753
    @poppydowse77533 жыл бұрын

    SO HELPFUL!!!!

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Really pleased you found it so helpful 😀

  • @pera_peric
    @pera_peric3 жыл бұрын

    Thank you!

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    you're welcome 😊

  • @mahimaali9795
    @mahimaali97952 жыл бұрын

    This was the last video I watched before my exam and it came up!!

  • @rip_6998

    @rip_6998

    Ай бұрын

    how did u do x

  • @mani-jx7nb
    @mani-jx7nb3 жыл бұрын

    Hi Miss Estruch, just wanted to say that your videos are saving my life :) question, what would fertilisation look like for the non-disjunction in meiosis 2 (polyploidy & aneuploidy) ?

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    It depends on the gametes made. For aneuploidy, n +1 or n-1 combing with a normal n gamete would result it trisomy or monosomy in the zygote. If it was a polyplooidy gamete, 2n, combining with a normal n gamete you'd get a 3n zygote which is polyploidy. The overall outcome is the same whether the mutation occurred in meiosis I or II. Hope that helps.

  • @easytolearn5275
    @easytolearn52753 жыл бұрын

    wondefully explained

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Thank you!

  • @khainojr2721
    @khainojr27213 жыл бұрын

    Miss it help me so much thank you.

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    So pleased it helped you!!!

  • @ardisrexha868
    @ardisrexha868 Жыл бұрын

    hi, what spec point is this under for aqa a level biology.

  • @nureeyakhan7451
    @nureeyakhan74513 жыл бұрын

    hi miss, love your videos, they're so helpful, thank you so much for making them :) at 1.30 you said 'diploid gamete' but I thought all gametes are haploid as they have half the usual number of chromosomes?

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    all gametes should be haploid, but due to non-disjunction in chromosome mutations, some can be diploid.

  • @ahmedsharaf2695
    @ahmedsharaf26952 жыл бұрын

    Thank you so much 👍👍👍

  • @MissEstruchBiology

    @MissEstruchBiology

    2 жыл бұрын

    You're so welcome ☺️ Hope it helps you

  • @The-Progress-Project
    @The-Progress-Project22 күн бұрын

    what topic is mutagenic agents?

  • @LakmalPerera-or3nx
    @LakmalPerera-or3nx Жыл бұрын

    teacher can you explain how to make 4n cells

  • @caitlinwhiteman8801
    @caitlinwhiteman8801 Жыл бұрын

    Hi, at 1:35 you said that polyploidy results in a triploid gamete instead of a diploid gamete. I'm a bit confused because I thought gametes are haploid? Do you mean the offspring will be triploid?

  • @MissEstruchBiology

    @MissEstruchBiology

    Жыл бұрын

    yes!!! That's right

  • @mynamemeanswish4445
    @mynamemeanswish44453 жыл бұрын

    You don't know how good you are:) thaks💙💙💙💙💙

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    awww thank you ☺😊

  • @iluvdawgs00
    @iluvdawgs00 Жыл бұрын

    Is this part of as lvl chap 5?

  • @nosleepdelirium1214
    @nosleepdelirium12147 ай бұрын

    Sorry just for clarification you don't ever have a diploid or triplioid gamete. Gametes are haploid so polyploidy creates a triploid zygote right ? I think ? Well you did explain this actually , I guess just a little misspoke in the beginning 😊

  • @joshuacottrell2742

    @joshuacottrell2742

    Ай бұрын

    Gametes are normally haploid as one gamete receives one copy when the chromatids separate in meiosis 2. If you get a non-disjunction mutation, you will get 2 copies in one gamete and 0 in the other. This means you have a diploid gamete and essentially an empty cell. This means you could potentially get a triploid zygote if the diploid gamete (from the non-disjunction e.g., in the Father) combines with a normal haploid (e.g., from the Mother) during random fertilisation. Hope this helps!

  • @mikail_medic862
    @mikail_medic8623 жыл бұрын

    I prefer to study together rather than with lecturers at my university (:

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    I hope these videos allow you to do that then ☺

  • @avrilstacy3133
    @avrilstacy31332 жыл бұрын

    It's a miracle that human survive. So many natural miscarriages occur due to undeveloped fetuses. I am a healthy biological female, but have mild endometriosis with some scar tissue in 1 fallopian tube which does effect conception in pregnancy. At my age now, I feel grateful that was my only medical issue I've ever had to deal with.

  • @MissEstruchBiology

    @MissEstruchBiology

    2 жыл бұрын

    So true. Glad you are otherwise doing g well 🙏🏻

  • @shhlarsd
    @shhlarsd3 жыл бұрын

    hi, why polyploidy rarely found in animals?

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Hi, Because it is usually lethal , meaning the fetus wouldn't survive if it was polyploidy.

  • @ell6311
    @ell63113 жыл бұрын

    Hey, could you tell me what topic gene mutations is in please

  • @MissEstruchBiology

    @MissEstruchBiology

    3 жыл бұрын

    Hello, it comes up on both topic 4 and topic 8 😊

  • @ell6311

    @ell6311

    3 жыл бұрын

    @@MissEstruchBiology thank you

  • @user-vq4qy2hq5i
    @user-vq4qy2hq5i4 ай бұрын

    Are we supposed to know this for AQA as our teacher told us this video specifically was off spec?

  • @MissEstruchBiology

    @MissEstruchBiology

    4 ай бұрын

    Non disjunction and chromosome mutations is in topic 4 for AQA A-level

  • @user-vq4qy2hq5i

    @user-vq4qy2hq5i

    4 ай бұрын

    @@MissEstruchBiology Do we need it in this level of detail, etc. with the name of each specific case?

  • @destinyosaghae
    @destinyosaghae3 ай бұрын

    Is polypoidy and aneuploidy on the spec?

  • @saraszymonczyk2814

    @saraszymonczyk2814

    Ай бұрын

    no

  • @reecehaddock8274
    @reecehaddock8274Ай бұрын

    What happens if an n+1 gamete fuses with an n-1 gamete

  • @MissEstruchBiology

    @MissEstruchBiology

    Ай бұрын

    Depends if it is the same chromosome that they have 1+ and 1- of. It would be exceptionally unlikely that would ever happen, but if it did then it would result in a 2n cell.

  • @favourebohon5259
    @favourebohon52592 жыл бұрын

    Hi Miss, I'm in Year 12. Thank you so much for your videos. Do we have to know the meiosis process for both non-disjunction mechanisms or is just the theory? Thank you.

  • @danielmoore4024

    @danielmoore4024

    Жыл бұрын

    Favour Ebohon, You will if you want to pass a standardised test, but if you want to actually be a biologist you can't keep swallowing what people tell you without challenging it. In the mid 19th century scientists twisted biology and pathology and because no one challenged the dogmatic assumptions there's now a lot of dogma in human biology. I challenge those who view themselves as scientists, they can never overcome my scrutiny because they are using dogma. If you want to see the real science you will have to leave the box. If you scrutinise what you've been taught you will be able to see most scientists are trying to prevent human evolution. I'll share just a little from scientists outside of the box not basing their work on man-made narratives, whenever the term "normal" is mentioned beware, you are heading towards science discourse. Molecular biologist Miroslav Radman writes, "Mutagenesis has traditionally been viewed as an unavoidable consequence of imperfections in the process of DNA replication and repair. But if diversity is essential to survival, and if mutagenesis is required to generate such diversity, perhaps mutagenesis has been positively selected for throughout evolution." Evelyn Fox Keller of MIT explains: "We now know that mechanisms for enduring genetic stability are a product of evolution. Yet a surprising number of mutations in which at least some of these mechanisms are disabled have been found in bacteria living under natural conditions. Why do these mutants persist? Is it possible that they provide some selective advantage to the population as a whole? Might the persistence of some mutator genes in a population enhance the adaptability of that population? Apparently so. New mathematical models of bacterial populations in variable environments confirm that, under such conditions, selection favors the fixation of some mutator alleles and furthermore, that their presence accelerates the pace of evolution." The mutants behind things like Down Syndrome, Autism, ADHD etc... offer some great advantages to the human race, diminishing the genes is a great risk because without those mechanisms there is no asurety of genetic stability pushing us in the direction of extinction. "You gotta challenge all assumptions. If you don’t, what is doctrine on day one becomes dogma forever after." John Boyd