This study investigates children's science learning in a nursery in Turkey. The participating children (aged 5 and 6) are from a socio-economically disadvantaged community. This is an ethnographic study that includes participant observations and audio recordings of classroom interactions based on a long-term basis. It takes a socio-cultural approach and uses the concept of speech genre [Bakhtin, M. M. 1986. "Speech Genres and Other Late Essays." Austin: University of Texas Press] to examine children's science learning. The findings highlight the role of the teacher in learning scientific concepts. It shows that the experiments enable the children to test and investigate scientific concepts. It also problematises the role of the teacher in structuring science activities and classroom talk by suggesting that teachers need to be explicit when they introduce children to concepts, rather than leaving technical knowledge for children to make inferences.