Can some one explain to me both processes in a SIMPLE form yet including A grade content , I don't understand all this chromosome stuff and pairing etc.
I do understand the dna zipping part from the mitosis process though.
I'm doing gcse ocr gateway science B , I understand each chromosome is a pair and that half DNA from each parent
Okay so have you any idea of the different phases of mitosis? To summarise:
1. Each chromosome replicates in S-Phase (before mitosis) so each cell has 96 chromosomes. The copies are called "sister chromatids" to the originals and are joined by a centromere.
2. Prophase is when the chromosomes supercoil, so we can view them under a microscope, and the nuclear envelope breaks down. Centrioles separate to opposite poles of the cell - these are what create spindle fibre to pull the sister chromatids.
3. Metaphase is when the chromosomes line up along the equator of the cell and attach to spindle created by the centrioles.
4. Anaphase is when the spindle fibres contract (shorten) and each sister chromatid is pulled to opposite poles of the cell. The centromere breaks in the process.
5. Telophase is when the cell begins to cleave into two daughter cells that are genetically identical to the original. The nuclear envelope reforms and the spindle fibres break down.
The process where the two new cells form is not actually mitosis but a process called cytokinesis shortly after telophase.
This is just mitosis, but learn this before meiosis. Remember: PMAT for the order of the phases.
Can you explain diploid and haploid please and other keywords involves In mitosis / meiosis. Thanks!
The diploid number of chromosomes is two sets of chromosomes - one set from mum, one set from dad. This is 46 in humans (23x2) and occurs in body cells eg skin cells, nerve cells. It's referred to as 2n.
Haploid is one set of chromosomes, this occurs in sex cells (gametes) such as sperm and egg in animals. When two sex cells combine in fertilisation the diploid number is restored. You can remember haploid as being half the number as haploid/half both begin with "ha".
What do you mean as sets? Do you mean pairs? And for the gametes when you say single set do you mean a single set of two choromosomes or just one individual chromosome?
What do you mean as sets? Do you mean pairs? And for the gametes when you say single set do you mean a single set of two choromosomes or just one individual chromosome?
Thanks
Each human body cell has 46 chromosomes, 23 from mum, 23 from dad. Gametes only have 23, so this is what I mean by sets.
When the gametes fuse in fertilisation, the body cell number of 46 is restored. There should be plenty of good pics online to explain it in a more visual manner.
Okay so have you any idea of the different phases of mitosis? To summarise:
1. Each chromosome replicates in S-Phase (before mitosis) so each cell has 96 chromosomes. The copies are called "sister chromatids" to the originals and are joined by a centromere.
2. Prophase is when the chromosomes supercoil, so we can view them under a microscope, and the nuclear envelope breaks down. Centrioles separate to opposite poles of the cell - these are what create spindle fibre to pull the sister chromatids.
3. Metaphase is when the chromosomes line up along the equator of the cell and attach to spindle created by the centrioles.
4. Anaphase is when the spindle fibres contract (shorten) and each sister chromatid is pulled to opposite poles of the cell. The centromere breaks in the process.
5. Telophase is when the cell begins to cleave into two daughter cells that are genetically identical to the original. The nuclear envelope reforms and the spindle fibres break down.
The process where the two new cells form is not actually mitosis but a process called cytokinesis shortly after telophase.
This is just mitosis, but learn this before meiosis. Remember: PMAT for the order of the phases.