CAIE A-Level Biology A2 14.2.1 Stomata Response to Environmental Changes Questions

There are more than 600 plant species in the genus Ipomoea. Many species are grown for their attractive flowers, and some species are used as crop plants.

Scientists investigated the response of stomata to changing carbon dioxide ( $\mathrm{CO}_{2}$ ) concentrations in the beach morning glory, I. pes-caprae.

The scientists placed I. pes-caprae plants in chambers. They measured the width of open stomata (stomatal apertures) after the plants had been exposed to different $\mathrm{CO}_{2}$ concentrations for 40 minutes. Light intensity and temperature were kept constant.

The relationship between $\mathrm{CO}_{2}$ concentration and the mean width of stomatal apertures is shown in Fig. 3.2.

In 2016, a study measured the atmospheric $\mathrm{CO}_{2}$ concentration as $400 \mu \mathrm{~mol} \mathrm{~mol}^{-1}$.

In the future, climate change may reduce water availability and increase atmospheric $\mathrm{CO}_{2}$ concentrations in some habitats.

Suggest how the stomatal response shown in Fig. 3.2 would allow I. pes-caprae to survive the effects of climate change.