Final answer:
The statement about carbon allocation between roots and leaves in plants is true. It reflects a critical trade-off that affects the plant's water absorption and nutrient uptake versus its potential for photosynthesis, which relies on leaf production.
Step-by-step explanation:
The statement that allocating carbon to the production of roots increases access to water and soil nutrients but limits carbon allocation to the production of leaves is TRUE. Plants face a trade-off between growth above and below ground. When a plant allocates more carbon to its root system, it strengthens its ability to absorb water and soil nutrients, which is crucial for its survival, especially in environments where water is scarce or nutrients are limited. However, this allocation comes at a cost, as it results in less carbon being available for the production of leaves, which are essential for photosynthesis, the process through which plants convert light energy into chemical energy. Photosynthesis is vital as it not only provides energy for plant growth but also oxygen for the environment. Consequently, this carbon allocation is a balancing act that affects a plant's overall ability to thrive.
According to water potential concepts and the role of water in plant biology, water potential decreases from the roots to the top of the plant, and water enters the plant through the root hairs and exits through the stomata (d). Moreover, for every carbon atom fixed into carbohydrates during photosynthesis, a significant amount of water is transpired through the stomata. Guard cells play a key role in this process (c), by regulating the opening and closing of stomata, which in turn affects both transpiration and photosynthesis.