Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain why a phenotype depends on both the genotype and the environment, and define phenotypic plasticity. (Guide: “Genotype is not the whole story”; Practice Q1)
- I can explain the two main ways the environment acts: by changing gene expression, or by changing how well a gene product works, without changing the DNA sequence. (Guide: “How the environment reaches the genes”; Practice Q2)
- I can explain temperature-dependent sex determination in reptiles, including the role of aromatase. (Guide: Worked example 2)
- I can explain seasonal coat colour, hydrangea flower colour, tanning, human height and weight, and yeast mating signals as examples of one genotype giving several phenotypes. (Guide: examples table; Practice Q2, Q5, Q6, Q7)
- I can explain why a phenotype caused by the environment is not passed on through the gametes. (Guide: “Common misconceptions”; Practice Q7)
Calculation and skills
- I can calculate means and percentage changes, dividing by the starting value. (Guide: Worked example 1; Practice Q4, Q7)
- I can estimate a pivotal temperature by interpolating to 50%. (Guide: Worked example 2, Figure 2)
- I can read a reaction norm and say which genotype is most plastic and whether genotype and environment interact. (Guide: Figure 1; Practice Q4)
- I can calculate a standard error and use ±2 SE to judge whether a change is likely to be real. (Practice Q7)
Reasoning
- I can design an experiment that separates genetic and environmental effects using clones, a common garden, or each individual as its own control. (Guide: Worked example 1; Practice Q3, Q5, Q7)
- I can identify confounded variables, such as day length and temperature in the wild, and design a test that separates them. (Practice Q5)
- I can use evidence to argue whether a signal acts by contact or by a released chemical. (Practice Q6)
- I can explain why a plastic response is not always helpful, for example when a cue no longer matches the conditions. (Guide: “Common misconceptions”; Practice Q5)
All ticked? Move on to Topic 6.1, DNA and RNA structure, or return to the course roadmap.