AP BIOLOGY

Detailed explanation-1: -When the genes are shared so it preserved the ancestor record where they share with each other and excludes the bacteria. And, if the DNA is the same for two organism so they would share the a common ancestor. hence, the last option is correct.

Detailed explanation-2: -Homologous structures If two or more species share a unique physical trait they may all have inherited this trait from a common ancestor. Traits that are shared due to common ancestry are homologous structures. The similar bone arrangement of the human, bird, and whale forelimb is a structural homology.

Detailed explanation-3: -Examples of marsupial mammals include kangaroos, wallabies, wombats, the koala, and the Tasmanian devil. These three extant mammal groups-monotremes, marsupials, and placentals-are monophyletic, meaning the members of each group descend from one common evolutionary ancestor.

Detailed explanation-4: -If different species share common ancestors, we would expect organisms to share similarities inherited from those ancestors. Features inherited from common ancestors-even if their appearance is quite different in close relatives-are known as homologies.

Detailed explanation-5: -In general, organisms that share similar physical features and genomes tend to be more closely related than those that do not. Such features that overlap both morphologically (in form) and genetically are referred to as homologous structures; they stem from developmental similarities that are based on evolution.