Wheres the picture for this
A common way that humans pollute water is through the addition of nutrients (fertilizers and sewage) to water as nonpoint source pollution. These added materials are full of nitrogen and phosphorus, two nutrients that encourage the growth of aquatic producers, such as algae.
Ans.
The codons show genetic codes, made up of triplet of nucleotides in DNA or RNA that code for specific amino acids. The different codes can code for a same a amino acid. When a substitutional mutation occurs in genetic material, it shows substitution of one nucleotide pair for another and leads to formation of a different codon.
The first mutation that leads to CAU to CAC, it will not show any potential damage as both CAU and CAC codons code for histidine amino acid.
The second mutation that leads to UGU to UGC will also not show any damage to protein as both of these codons code for cysteine amino acid.
The third codon, that results UCU to UUU will cause a potential damage to protein as UUU codes for phenyl alanine (an aromatic, non-polar amino acid) and UCU codes for serine (a polar amino acid).
Thus, the correct answer is 'option C).' as in a protein, substitution of serine with phenylalanine will lead to change in structure and function of that protein.
Although, I'm not sure about the entirety of this question, when reviewing claims and evidence, check your sources to make sure they are reliable.