meiosis, meitosis

[newnerd]

Okay so maybe I am overlooking something very simple but I am having trouble understanding how it is said that each human diploid cell contains 46 chromosomes or 23 pair of homologous chromosomes. But when I look at how meiosis occurs I am only seeing 4 pair of chromosomes which go through meiosis 1 and turn haploid before going through meiosis 2. What am I missing? when I think of 46 chromosomes I envision a picture of an entire karyotype and that shows a lot more chromosomes that what I see during meiosis.

Also during meiosis, lets say these were my cells going through meiosis. During the crossing over phase this is the crossing over of MY mom and dad's chromosomes which I inherited to form a new hybrid version? Just to make sure I understand this correct also

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[efle]

Mitosis with mom ) and dad I for one chromosome:

cell has )I --> copies made )( II --> splits back to )I in two cells

This happens for 23 chromosomes

Meiosis:

cell has )I --> copies made )( II --> split #1 )( in one cell II in the other --> split #2 four cells, two get a ) two get a I

This also happens for all 23 chromosomes.

The crossing over phase is during ")( II" where the inner two can swap some DNA, so yes you are creating a "new" chromosome which is a mix of both parents that you can pass on

 

[efle]

Mitosis with mom ) and dad I for one chromosome:

cell has )I --> copies made )( II --> splits back to )I in two cells

This happens for 23 chromosomes

Meiosis:

cell has )I --> copies made )( II --> split #1 )( in one cell II in the other --> split #2 four cells, two get a ) two get a I

This also happens for all 23 chromosomes.

The crossing over phase is during ")( II" where the inner two can swap some DNA, so yes you are creating a "new" chromosome which is a mix of both parents that you can pass on

 

[caxoo]

Textbooks draw out just 4 because drawing out all 23 would take up the entire page and be really tedious

 

[MrLogan13]

Only 4 pairs are illustrated, but occurs for the other 19 pairs too.

 

[newnerd]

Only 4 pairs are illustrated, but occurs for the other 19 pairs too.

Textbooks draw out just 4 because drawing out all 23 would take up the entire page and be really tedious

ok that makes sense. thx 🙂

 

[Ismet]

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