Frederick griffith was one of the leading scientists looking at the genetic role of dna. he was working on two strains of streptococcus pneumoniae: the rough strain (r) did not cause pneumonia, but the smooth strain (s) did. when griffith heat-killed the s strain and gave both the heat-killed s strain and the r strain to mice, the mice developed pneumonia and died. what happened in this experiment that caused the mice to develop pneumonia?

One of the newest applications of cell technology is called cybrid embryos. this process involves replacing the nuclear material of an animal cell with human nuclear material. how might this process affect public policies about research by using stem cells? the same policies and concerns about the use of human embryonic stem cells would most likely apply. the embryos would most likely be treated like traditional animal embryos and regulated accordingly. the process of forming cybrid embryos would most likely be banned by government regulators. the embryos would be treated as regular cells because they are not fully human in origin.