Answer:
b because I learned it in 4th grade
Explanation:
b
<span>In your cell, this is where the endomembrane system comes in a cell image because one is studded with small ribosomes and one is not.it does not help the cell move.IT IS not a function of the endomembrane system of the cell</span>
Sister chromatids have different alleles although carry same genes on same loci. So if it doesn't happen so, like if there are same alleles on sister chromatids then there is a problem in its formation. i.e., male and female alleles haven't contributed equally ( may be an error during their segregation process ). And obviously it doesn't happen in a real cell so we must understand this point. Because normally whenever it happens there's one half from the male and one half from the female. (i.e. maternal and paternal alleles contribute equally).
I hope you get the answer!!!