AP BIOLOGY

Detailed explanation-1: -Because an insertion or deletion results in a frame-shift that changes the reading of subsequent codons and, therefore, alters the entire amino acid sequence that follows the mutation, insertions and deletions are usually more harmful than a substitution in which only a single amino acid is altered.

Detailed explanation-2: -Frameshift mutations are among the most deleterious changes to the coding sequence of a protein. They are extremely likely to lead to large-scale changes to polypeptide length and chemical composition, resulting in a non-functional protein that often disrupts the biochemical processes of a cell.

Detailed explanation-3: -A single nucleotide mutation will result in harmful mutations in an organism. Therefore, the given option is true.

Detailed explanation-4: -In case of deletion or insertion of a particular fragment of the gene, deletion could be more harmful than insertion, because the deleted fragment of the gene will never be replaced at exact size and exact position of the disabled gene.