silly order
Have you noticed how DNA, genes, natural selection, evolution etc are scrambled between B1 and B2. I really don't see how the kids are supposed to "get it" when we have to teach them about genes in yr 10 (as a fact, but not about DNA) and then revisit it again in B2. We need to construct knowledge by starting with cell structure, nucleus, DNA, chromosomes, genes, natural selection, selective breeding, genetic engineering as a logical sequence.
Mike Bell, science teacher and trainer in evidence-based practice