A Level Biology Practice Exam

What does the symplast refer to in plant cells?

1. The space between plant cells

2. The continuous cytoplasm connected through plasmodesmata

3. The rigid cell wall structure

4. The external environment around the cells

The correct answer is: The continuous cytoplasm connected through plasmodesmata

The term "symplast" refers specifically to the continuous network of cytoplasm that exists in plant cells, which is interconnected through small channels called plasmodesmata. These plasmodesmata allow the cytoplasmic connections between adjacent plant cells, facilitating communication and the movement of water, nutrients, and signaling molecules. This feature is particularly important in plants, as it enables them to function as a unified organism, allowing cells to share resources and information effectively. In contrast, the other options describe different components or aspects of plant structure. The space between plant cells refers to the apoplast, which is the extracellular space, while the rigid cell wall is a structural component that serves to support and protect the cells, but does not involve direct cytoplasmic connectivity. The external environment around the cells does not pertain to the internal functions or connections of the cells themselves. Therefore, the correct definition of symplast emphasizes its role in the interconnectivity of cytoplasm through plasmodesmata, facilitating intercellular transport and communication.