AP BIOLOGY

Detailed explanation-1: -The majority of mutations have neither negative nor positive effects on the organism in which they occur. These mutations are called neutral mutations. Examples include silent point mutations. They are neutral because they do not change the a mino acid s in the proteins they encode.

Detailed explanation-2: -No; only a small percentage of variants cause genetic disorders-most have no impact on health or development. For example, some variants alter a gene’s DNA sequence but do not change the function of the protein made from the gene.

Detailed explanation-3: -How can mutations affect organisms? Mutations can affect an organism by changing its physical characteristics (or phenotype) or it can impact the way DNA codes the genetic information (genotype). When mutations occur they can cause termination (death) of an organism or they can be partially lethal.

Detailed explanation-4: -Silent mutations occur when the change of a single DNA nucleotide within a protein-coding portion of a gene does not affect the sequence of amino acids that make up the gene’s protein.

Detailed explanation-5: -In a silent mutation, a nucleotide is substituted but the same amino acid is produced anyway. This can occur because multiple codons can code for the same amino acid. For example, AAG and AAA both code for lysine, so if the G is changed to an A, the same amino acid will form and the protein will not be affected.