What does the atomic mass of an element represent ?

Which of the following is an example of an environmental change the affected the evolution of life a. volcanic activity b. changes in climate c. mountain building d. all of the above

Which of the following matches the organisms described with the correct domain? a. bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycanb. archaea--multicellular, eukaryotic organisms that do not have cell wallsc. eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sourcesd. bacteria--unicellular, eukaryotic organisms that always lack cell walls

When explaining dominant and recessive traits to a younger family member, they respond, "well chances are i can probably taste ptc, since dominant traits are more common." how might you address this misconception?