mitosis/meiosis--haploid diploid thing?

Question

i dont understand the haploid / diploid thing in mitosis and meiosis. help?
thanks <3

am i correct in believing that in humans (mitosis) its always diploid. but in meiosis it goes from diploid to haploid to haploid?


<3 thanks

Answer 1

yes, mitosis is from diploid to diploid; that is, the cell is making an exact copy of the DNA in the cell. That's all mitosis is usually for in humans--replication.
as for meiosis, this process is used in sexual reproduction, and is a lot more complicated. DNA within the cell replicates, and splits. Before it splits again, the DNA may "cross over" and make brand new genes. (This results in a difference between parents and their children). Then, the two new cells split again, ending with four new cells, which are haploid. It becomes even more complicated in humans and in organisms that are haploid to begin with, but that is another answer to another question... I hope this helped you somewhat.

Answer 2

Well, it is not so complicated. I will try to put it in the simplest way.
First, you know that fertilization means the union of an ovum (female reproductive cell) and a sperm (male reproductive cell) to make the zygote (first cell formed, that further divides to make the whole human being).
Each of the ovum and the sperm are haploid cells (having half the genetic information of the mother or father), so when they unite together they produce a baby having characteristics of both father and mother.
Thus logically speaking. Ovum(23 ch)haploid+ sperm (23 ch)haploid= zygote(46 ch)diploid.
when zygote is formed, all the cells divide by mitosis, inorder to produce more cells to make organs for the formed baby.

So, again:
Mother's cells(diploid, 46 ch) divide by meiosis to produce the ovum (haploid, 23 ch).
Father's cells (diploid, 46 ch) also divide by meiosis to produce sperm (haploi, 23 ch).
ovum (23 ch)+ sperm (23 ch)= zygote(46 ch) which grows to a full human being (baby of course).

So, meiosis is only related to the reproductive cells, because if there was no meiosis what will the baby be???? 46+46=92!!!!!!!92 ch is not human, right!!!!!!!!

As for mitosis, it is the way our somatic cells (non reproductive cells) divide to produce new cells that are completely identical to the original ones. For example, if you have a wound, new skin cells are produced by mitosis inorder to take the place of the old dead cells. Same during growth, new cels are produced by mitosis to make your bone longer, to make you more muscles, and so on......

I know that it is a bit confusing, but I hope that this could help. Good luck.

Answer 3

ok, most human cells are diplod meaning they have 2 chromosomes in the cell. Only sex cells are haploid, meaning they have on chrmosome. This because sex cells unite and form a diploid cell.

In meiosis Iyou go from diploid (2n), you dicve to get 4n, then you divide the cells and end up with 2n cells.

In meiosis II those 2n cells divde to become haploid and form for 1n cells wich are each genetically different due to crossing over (whch means section of different chromosomes switch places to creat genetic variability)

Answer 4

You don't call it anything, its just 2 processes happening simultaneously so just refer to it as Diploid (x2) at leest that's what i think...