Meiosis is referred to as reduction division. Explain why meiosis is needed in the life cycle of a sexually reproducing organism.
Name two examples of environmental conditions that influence plant phenotype, other than mineral deficiency. For each one, describe the way in which it changes the phenotype.
Explain why mutations matter in selection.
Using Fig. 3.1, describe how the low phosphate soil type affects root growth compared with the full nutrient soil type, for both populations of thale cress.
Fig. 3.2 gives the equation for finding the value of $t$: $t = \frac{|\bar{x}_1 - \bar{x}_2|}{\sqrt{\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2}}}$ Apply the formula in Fig. 3.2 to work out the value of $t$. Show your working.
Use your calculated value of $t$ to judge whether the null hypothesis should be accepted or rejected.