“The Americas were discovered in 1492, and the first Christi…

“The Americas were discovered in 1492, and the first Christian settlements established by the Spanish the following year…. [I]t would seem… that the Almighty selected this part of the world as home to the greater part of the human race…. [T]heir delicate constitutions make them unable to withstand hard work or suffering and render them liable to succumb to almost any illness, no matter how mild. . . . It was upon these gentle lambs… that, from the very first day they clapped eyes on them, the Spanish fell like ravening wolves upon the fold, or like tigers and savage lions who have not eaten meat for days. . . . The native population, which once numbered some five hundred thousand, was wiped out by forcible expatriation to the island of Hispaniola.” Bartolomé de Las Casas, 1552   An implication of Las Casas’ argument is that a major cause of the decline of the native populations in the Americas after 1492 was the  

You are interested in the role that gene X plays in embryoge…

You are interested in the role that gene X plays in embryogenesis.  Specifically, you want to visualize via brightfield microscopy any morphological changes that may occur over the course of development in the absence of gene X.  Which model organism would be the best choice:

The generation of the knockout mouse model provided an impor…

The generation of the knockout mouse model provided an important tool for scientists to study genetics in mammals.  During the creation of a knockout line, a chimera is produced after implantation of the transfected embryo (embryo containing the desired genetic deletion) into the surrogate mother.  Which of the following best explains why?