Answer:
If crossing over doesn’t occur, then 2 out of the 4 daughter cells would be identical.
We have 46 chromosomes and are diploid meaning we got 1 set (23 chromosomes) from our mom and 1 set (23 chromosomes) from our dad.
In prophase 1, homologous chromosomes associate (chromosome #1 from dad and chromosome #1 from mom. They both code for the same things, but they are NOT identical)
Let’s compare mitosis to meiosis
On the left, see how in mitosis all chromosomes (even homologous) line up in single file (imagine all 46 lining up individually). When anaphase splits the sister chromatids (which are identical) in mitosis, each daughter cell gets the exact same genetic info.
(they get both homologous chromosomes: 1 from dad (yellow)and 1 from mom (purple) resulting in a full diploid set)
On the right in meiosis, see how the homologous chromosomes associate and will split? Chromosome #1 from mom (purple) is going to the left daughter cell while chromosome #1 from dad (yellow) is going to the right daughter cell. This means the two daughter cells will only have 1 set for chromosome #1 (either moms or dads but NOT both) and become haploid (1 set of 23 chromosomes)
Again in mitosis, all 46 lined up individually, but in meiosis the 23 from mom and 23 from dad first associate and each orient to decide which daughter cell gets the dads chromosome or the moms chromosome. They assort independently meaning just because dads chromosome #1 went to the left DOESN’T mean that dads chromosome #2 or #3 will go to the left. This gives a unique pattern of 23 chromosomes for the 2 daughter cells of meiosis 1 (a various mixture of moms and dads, but it is possible to result in a daughter cell with just moms and just dads set, though this would be a very small probability like 1 in 2^23 )
So each daughter cell of meiosis 1 is a haploid set (only 1 set instead of 2) and the opposite of the other (since 1 has fathers while the other has mothers for the same chromosome)
Meiosis 2 is just like mitosis. Here the sister chromatids separate producing 2 identical daughter cells
(identical if crossing over doesn’t occur. Crossing over only occurs on adjacent homologous chromatids)
If crossing over doesn’t occur then both sister chromatids are identical so that 2 out of 4 daughter cells will be exactly identical haploid sets. The other 2 are identical to each other as well.
Explanation:
