Problem 96 - Objective Biology for NEET

Question

Radial vascular bundle can be seen in (a) Leaf (b) Dicot root (c) Stem (d) Flower

Step-by-Step Solution

Answer

The correct answer is (b) Dicot root.

Step 1: Understanding the terminology

A vascular bundle is a part of the transport system in vascular plants. The transport itself happens in vascular tissues, which are made up of xylem and phloem. They are arranged in a circle within the pericycle, a sheath of cells which makes up the radial bundle.

Step 2: Identify the correct option

Radial arrangement of vascular bundles is most commonly seen in roots. In radial arrangement, xylem and phloem are arranged on different radii. Hence they are typically found in the roots of dicotyledonous plants.

Step 3: Eliminate wrong options

Option (a) Leaf, (c) Stem, and (d) Flower can be ruled out as radial vascular bundles are not typically found in these plant parts.

Key Concepts

Vascular Tissues

Vascular tissues are crucial components in the anatomy of vascular plants, responsible for the transport of water, nutrients, and sugars throughout the plant. These tissues make up an essential part of the plant's vascular system, and they facilitate the movement of substances necessary for growth and development.

• The two primary types of vascular tissues are xylem and phloem.
• They work together to create a continuous pathway for the flow of different materials.

Understanding vascular tissues is key when studying how plants distribute necessary resources from roots to leaves. These tissues help maintain the plant's structure and can be found organized in various arrangements, including radial bundles.

Xylem and Phloem

Xylem and phloem are the two types of vascular tissues in plants, each with distinct roles. Xylem is primarily responsible for transporting water and dissolved minerals absorbed from the soil. It moves these substances from the roots upwards to the rest of the plant. Xylem also provides structural support due to its rigid cells, which help in maintaining the plant's posture.

• Functions majorly in water conduction.
• Contains tubular structures that facilitate upward transportation.

Phloem, on the other hand, transports the sugars produced by photosynthesis from the leaves to other parts of the plant. These sugars are crucial for energy and growth.

• Moves nutrients and organic compounds both upward and downward.
• Contains sieve-tube elements and companion cells that aid in the transportation process.

Dicot Root

Dicot roots showcase a fascinating example of radial vascular bundles. In these roots, the vascular tissues are organized in a specific pattern where xylem and phloem are arranged radially.

• In a dicot root, xylem is located at the center, arranged in a star-like pattern, with phloem occupying the spaces between the xylem arms.
• This radial arrangement facilitates efficient transport and storage of nutrients.

The arrangement in dicot roots helps to support the plant's structure and enables the efficient conduction of water and nutrients, which are vital for plant health.

Plant Anatomy

Plant anatomy is the study of the internal structure of plants. This field covers how different parts of plants, such as roots, stems, leaves, and flowers, are developed and function.

• It explores how the arrangement of tissues like xylem and phloem contributes to the plant's overall functioning.
• By studying plant anatomy, we learn how plants transport essential substances efficiently throughout their structure.

Essentially, understanding plant anatomy allows us to appreciate the complexity of plant life and how various structures are intricately connected to ensure survival and growth in a myriad of environments.