In this article, we analyze how high school students from a Full-Time Public School in the city of Campinas define human characteristics based on a set of activities in the elective course named I, human? Science and Science Fiction. Throughout the course, we proposed a construction of an interactive futuristic science fiction tale, inspired by a Bruce Sterling tale, in which students were characters in the story. Among interactions, they should build a clone and talk about its characteristics. During this activity, students pointed out similar or different characteristics between themselves and their clones. In addition, students conceptualized the clones as either human or non-human. Although most students understand that clones are human beings, there was no unanimity about what defines the clone as human, ranging from anatomical and physiological boundaries (skin, eyes, hair, eating, sleeping), cognitive (ability to learn and to think), even personality (desire to dance, sing, be brave, extrovert). We consider it important to have a place in school that are able to introduce debates about new scientific technologies, in order to provide students with a deeper understanding of how science is present in our daily lives and some effects on the definitions of human beings beyond organic boundaries.