What is the role of the cambium tissue in the stem of a plant?
A. It forms new tissue that causes the stem to grow thicker.
B. It stores sugars for later use by the stem.
C. It forms flowers and fruits for reproduction.
D. It covers and protects living tissue in the stem.
The Correct Answer and Explanation is:
The correct answer is A. It forms new tissue that causes the stem to grow thicker.
The cambium is a layer of actively dividing cells in the stem and root of a plant, crucial for the plant’s growth. It is part of the vascular tissue, which includes the xylem and phloem, and is located between these two tissues in the stem. The cambium plays a significant role in secondary growth, which is responsible for increasing the girth (thickness) of the plant.
In the process of secondary growth, the cambium produces new cells in two directions. On the inner side, it forms xylem cells, which are involved in the transport of water and minerals from the roots to the leaves. On the outer side, it produces phloem cells, which transport sugars and nutrients from the leaves to the rest of the plant. The production of these cells causes the stem to thicken over time. This thickening process allows the plant to support more leaves and branches, as well as provide more capacity for water and nutrient transport.
This type of growth occurs primarily in woody plants, such as trees, but can also happen in some herbaceous plants. As the cambium continues to generate new tissue layers, the old xylem becomes heartwood, providing structural support to the plant, while the newer xylem is responsible for the plant’s current water conduction needs.
The other options are not correct in relation to the cambium tissue:
- B. It stores sugars for later use by the stem: The storage of sugars is primarily done by specialized tissues like parenchyma, not the cambium.
- C. It forms flowers and fruits for reproduction: Reproductive structures like flowers and fruits are formed by different parts of the plant, primarily from the meristematic tissues responsible for reproduction.
- D. It covers and protects living tissue in the stem: Protection is mainly the role of the epidermis or the periderm, not the cambium.
Thus, the cambium’s primary role is to form new tissue that contributes to the plant’s secondary growth, making the stem thicker.