Thylacosmilus is a marsupial, and Smilodon is a mammal. Thylacosmilus and Smilodon both have saber teeth, but they do not share an ancestor that had saber teeth. What are saber teeth for these organisms?
a. analogous structures
b. homologous structures
c. vestigial structures
d. mutated structures

Which of the following statements best describes the quantity theory of inflation? a. inflation occurs because production cost rise and this cost increase is passed on to consumers in the form of higher prices b. inflation occurs because there is too much money in the economy c. inflation occurs because demand of good and services exceeds existing supplies d. none of these