Select the root cells that contain permeases to do active transport:
a. parenchyma b. pericycle c. XVMs d. a and b e. All of the above
The correct answer and explanation is:
The correct answer is d. a and b.
Explanation:
Active transport is the process of moving molecules across a cell membrane against their concentration gradient, requiring energy in the form of ATP. In plants, this process often involves specialized proteins known as permeases, which are responsible for the transport of substances across membranes.
- Parenchyma cells:
Parenchyma cells are the most common type of plant cell and play a critical role in storage, photosynthesis, and the transport of water and nutrients. These cells contain permeases, which are essential for the active transport of substances such as ions, sugars, and amino acids across the plasma membrane. In roots, parenchyma cells actively transport nutrients from the soil into the plant’s vascular system. - Pericycle cells:
The pericycle is a layer of plant cells located just inside the endodermis of the root. These cells are responsible for the formation of lateral roots and also play a role in the active transport of nutrients. Pericycle cells contain permeases that help to transport nutrients such as potassium, calcium, and other essential ions into the vascular tissue of the root, where they can then be transported throughout the plant. - XVMs (Xylem Vessel Elements):
Xylem vessel elements are specialized for the transport of water and minerals from the roots to the rest of the plant. However, these cells do not have permeases for active transport. Instead, they primarily rely on passive transport mechanisms such as capillary action and transpiration to move water and nutrients.
Thus, the root cells that contain permeases for active transport are primarily parenchyma and pericycle cells, making the correct answer d. a and b.