Buy Beats By Dre,Dre0454,paper provides an overview of that
This paper presents an introduction to Project MaRC. The goal of Project MaRC is to study, in very broad Buy Beats By Dre terms, what students know about scientific representations and what is possible for them to learn. We use the Cheap Beats By Dre Headphones term meta-representational competence (MRC) to describe the full range of capabilities that students (and others) have concerning the construction and use of external representations. As part of our project, we are engaging in an analysis of the nature of MRC, and we have begun to explore instructional implications. This introductory paper provides an overview of that work, including its goals and results, and it also provides an introduction to the four following papers in the issue. Isolation and culture procedures were adjusted to assure over 60% division in tobacco mesophyll protoplasts within 3 days of in vitro culture in liquid medium. The incorporation rates of radioactive precursors of DNA, RNA and protein were followed in such newly isolated protoplasts. It was found that thymidine incorporation peaked at 48 h of culture. A gradual increase of uridine incorporation started after 2 h of culture and was strongly accelerated after a further 10 h. A similar pattern was observed for leucine incorporation. The omission of α-naphthaleneacetic acid and 6-benzylaminopurine prevented the later increase in RNA and protein precursors' incorporation.