AP PSYCHOLOGY

Detailed explanation-1: -A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.

Detailed explanation-2: -Answer and Explanation: Accidental alterations during DNA replication that give rise to variations in organisms are mutations (option b). If fixed by replication, mutations are stably inherited for subsequent generations. Mutations can be beneficial, neutral, or detrimental to organisms.

Detailed explanation-3: -Mutations of DNA do not occur as randomly as previously assumed, according to new research from Max Planck Institute for Biology Tübingen in Germany and University of California Davis in the US.

Detailed explanation-4: -Mutations result either from errors in DNA replication or from the damaging effects of mutagens, such as chemicals and radiation, which react with DNA and change the structures of individual nucleotides. All cells possess DNA-repair enzymes that attempt to minimize the number of mutations that occur (Section 14.2).

Detailed explanation-5: -Gene mutations are permanent changes in DNA gene sequence. They can arise during normal DNA replication or in response to environmental factors. There are many classes of gene mutations. Certain mutations cause disease.