Question

Which is present in the vascular bundles of gymnosperms? (a) Tracheids (b) Vessels (c) Companion cells (d) All of these

Short answer

The correct answer is (a) Tracheids.

Step-by-step solution

Vascular Bundle in Gymnosperms

Gymnosperms, being vascular plants, contain vascular tissue for transport of water and nutrients. Their vascular bundles primarily consist of tracheids, which are tubular cells that transport water and solutes.

Analyze the Options

Vessels and companion cells are typically found in angiosperms, not gymnosperms. Only one of the given options, tracheids, is generally found in gymnosperms.

Conclusion

Based on the structural analysis of gymnosperms and the components of their vascular bundles, the correct answer is (a) Tracheids.

Key concepts

Tracheids

In gymnosperms, tracheids play a critical role in the plant's vascular system. These are elongated tubular cells found in the xylem, which is one part of the vascular tissue. The main function of tracheids is to transport water and dissolved minerals from the roots to various parts of the plant. This transport is essential for the plant's survival and growth.
Tracheids have thick, lignified cell walls that provide structural support to the plant. This structure not only facilitates efficient water transport but also helps the plant withstand various environmental stresses, such as wind and drought.
Unlike vessels, which are found in angiosperms, tracheids do not have perforations. Instead, they rely on pits—small openings in the cell walls—to connect with other tracheids, allowing water to pass between them. This design makes tracheids less efficient than vessels in water conduction but more suited to the overall needs of gymnosperms.

Vascular Bundles

Vascular bundles are critical components in the vascular systems of plants, including gymnosperms. They function as the plant's transport network, moving water, nutrients, and sugars to all parts of the plant.
In gymnosperms, the primary components of vascular bundles include tracheids for water transport and phloem for transporting organic nutrients. Unlike in angiosperms, vessels are absent in gymnosperms, and companion cells are not present. This highlights the importance of tracheids in gymnosperms' vascular bundles.
The arrangement of these bundles typically follows a specific pattern in stems and roots. They often appear as concentric circles or scattered clusters, providing both strength and flexibility to support the plant's structure. Understanding how these components work together in gymnosperms helps you appreciate their specialized adaptations for growth and survival.

Water Transport

Efficient water transport is vital for the growth and functioning of gymnosperms. The process begins when water absorbed by the roots moves upward through the plant in the tracheids located within the xylem. This movement is driven by several factors, including root pressure, capillary action, and transpiration pull.
Root pressure occurs when the roots absorb water from the soil, creating a push that moves water upwards. Capillary action further assists this transport due to the adhesion and cohesion forces between water molecules and the walls of the tracheids. Transpiration, the evaporation of water from plant leaves, generates a pull that draws water from the roots up through the tracheids.
These processes ensure that water reaches all parts of the plant, delivering the necessary nutrients while maintaining turgor pressure for structural stability. The seamless coordination among various parts of the vascular system highlights gymnosperms' evolutionarily refined water transport mechanisms.