Our year 9 students are learning about plant growth, photosynthesis, respiration and plant produce. They carried out an investigation to explore germination of cress seeds in dark and light conditions. The picture  shows the growth in dark (yellow) and light (green). The students concluded that light is one of the factors needed for photosynthesis to happen and in the absence of light the leaves turn yellow due to the absence of chlorophyll. It was also evident that the germination process is faster in the dark as the plant growth hormones work best in the dark. A few students measured the length of the stems and worked out that the stems of the cress plants (in the dark) were four times longer than those in the light.