Certified Professional Horticulturist (CPH) Practice Exam

If a shade-loving plant is moved into full sunlight, what plant process would be adversely affected immediately?

1. Respiration

2. Flower formation

3. Seed production

4. Photosynthesis

The correct answer is: Photosynthesis

When a shade-loving plant is moved into full sunlight, the plant's ability to photosynthesize is immediately impacted. Shade-loving plants are adapted to low light conditions and typically have a different set of photosynthetic pigments and leaf structures suited for those environments. When exposed to intense sunlight, they may not have the capacity to effectively manage the increased light intensity, leading to potential damage to the chloroplasts. In full sunlight, these plants can experience photoinhibition, where the rate of photosynthesis may decline despite the increase in light levels due to the stress caused by excess light energy. Additionally, the plant may suffer from water loss through increased transpiration rates under high light, further worsening its ability to photosynthesize. While respiration, flower formation, and seed production are important processes for plant health and reproduction, the immediate adverse effect of moving a shade-loving plant into bright light centers around the photosynthetic process, making it the most critical concern at that moment.