Thank you for the video ma'am. I am a bit confused that DNA replication occurs in interphase before Meiosis 1 begins just as Mitosis does. How does Meiosis 1 form a haploid number of chromosomes in the 2 unidentical daughter cells. In diagrams for mitosis the centromeres of the chromosomes split and are pulled apart but because of replication each daughter cell has a diploid number of chromosomes but in Meiosis 1 the whole recombinant chromosomes are pulled apart forming the two unidentical daughter cells with a haploid number which then go through Meiosis 2 without replication and form 2 more unidentical haploid cells. I feel I'm missing something...
Hi Emily so you are right both mitosis and meiosis use DNA replication to double the amount of chromatids. In mitosis we separate the chromatids by the centromere. In meiosis 1 we separate the homologous pairs first (which halves the chromosome number) then we in meiosis 2 we separate the chromatids. Keeping the haploid number just maintaining the haploid single stranded chromosomes
I have a question---after meiosis 1 when you have two unique daughter cells are they diploid or haploid? And how can I easily identify diploid vs haploid? I tend to get confused with those. Thank you!
They are haploid. The only way to identify them is knowing the original amount of chromosomes which they often tell you. Another way is to look for homologous pairs being separated or when the chromatids have separated.
The truth is the word is still applicable but most pupils don't use it correctly. I still use it when I teach my children. I am a senior marker at the end of the year exams and I still accept it.
Hey Miss Angler! I trust that you’re well 🤍 question: could we say that a homologous chromosome is a pair of chromosomes that carry corresponding genetic* information?
End of meiosis 1 you have 2 haploid cells. The chromosomes still have a centromere so in Meiosis 2 we need to separate them. At the end of meiosis 2 we will take those two cells, divided them again and get 4 non-identical cells that are haploid. You have now separated the centromeres for single stranded chromosomes.
Interphase is a phase that occurs prior meiosis. That's why Ms Angler explained it so that we can be able to understand what happens BEFORE prophase 1 and explain it if we're examined on that
Chiasma/chiasmata is a point where the homologous pair touch each other during crossing over whereas bivalents are the chromosomes during/after crossing over. They are called bivalents during crossing over or after it . Not sure if you quite understand or
and also is it wrong for me to mention the process of synapsis because my teacher said it was wiped out of the curriculum I always mention it and I feel like am going to get marked incorrect
At the end of the year exams its still accepted so your teacher should still accept it. ( I am a senior marker at the end of the year so I do have experience on this)
