Grade 12 Biology

Grade 12 biology is the year the subject becomes molecular. Chromosomes and DNA, variation and genetics, and biotechnology all depend on a clear mental picture of how genetic information is stored, copied and expressed. We build that picture carefully with diagrams of the double helix, replication and protein synthesis, because students who cannot picture the process cannot answer the questions about it.

Genetics continues from Grade 10 but at a higher level, including linkage, crossing over and multiple alleles. The method remains the same — set out the cross, state the gametes, count the offspring — and students who kept that habit from Grade 10 find the extension straightforward.

Homeostasis and coordination are examined as systems, and the best preparation is to practise explaining what happens, in order, when a condition changes. That is exactly the shape of the answer the examiner is looking for.