This topic considers the following biological principles through the context of the genetic disease cystic fibrosis: the properties of and transport of materials, across cell membranes and gas exchange surfaces, DNA structure and replication, protein synthesis, enzymes and monohybrid inheritance through the context of the genetic disease cystic fibrosis. The topic also allows for discussion of the social and ethical issues surrounding the genetic screening for genetic conditions.
Students should be encouraged to carry out a range of practical experiments related to this topic in order to develop their practical skills. In addition to the core practicals detailed below, possible experiments include investigation of the effect of surface area to volume ratio on uptake by diffusion, examination of slides of alveoli to observe the features that aid diffusion into the bloodstream, investigation of osmosis and diffusion across membranes, and investigation of inheritance using, for example, corn ears.
Opportunities for developing mathematical skills within this topic include calculating areas of circumferences and areas of circles, surface areas and volumes of rectangular blocks and spheres, using ratios, fractions and percentages, plotting two variables from experimental or other data, determining the slope and intercepts of a linear graph, understand that y=mx+c represents a linear relationship, drawing and using the slope of a tangent to a curve as a measurement of rate of change, understanding simple probability and completing a statistical test.