sludge
<span>Sewage treatment is also known as wastewater treatment. It is
a process whereby contaminant is removed from wastewater. Thus, chemical,
biological and physical process are commonly used to remove contaminants from
wastewater and the by-products of wastewater treatment is usually inform of
solid waste known as sewage sludge.</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!!!
Answer: Allows a magnified 3-Dimensional perspective when dissecting. This enables more accuracy in movements.
Explanation: